p.e.i. water quality interpretive report 1999 · 2004. 1. 5. · p.e.i. water quality interpretive...

P.E.I. Water Quality

Interpretive Report

1999

Environment EnvironnementCanada Canada

Technology and Environment

P.E.I. Water Quality

Interpretive Report

George SomersBruce RaymondWilliam Uhlman

Prepared forCanada - Prince Edward Island

Water Annexto the

Federal/Provincial Framework AgreementFor Environmental Cooperation In

Atlantic Canada

1999

Environment EnvironnementCanada Canada

Technology and Environment

Canada - Prince Edward Island Water Annex Water Quality Interpretive Report

i

Executive Summary

The Province of PEI and Environment Canada cooperatively monitor a long-termnetwork of water quality and quantity stations in a number of PEI watersheds. Currentlyfalling under the auspices of the Canada-PEI Water Annex to the Federal ProvincialFramework Agreement For Environmental Cooperation in Atlantic Canada, this workincludes monitoring completed under a number of programs, at some locations for aslong as thirty years. Last reported on in 1978, this report provides an overview of thecurrent conditions and documents long-term trends in water quality identified by theseprograms.

The water quality network currently includes stations in five watersheds andincorporates groundwater, fresh surface water and estuarine water. Samples arecollected at regular intervals on a year round basis. The watersheds were selected toreflect a range of land-uses from mostly forested to largely agricultural, and a range ofstream sizes. The data set utilized for this report comprises samples from the currentnetwork but also includes other historic samples contained in the Environment CanadaEnvirodat database. In some cases, there is a wide variety of parameters analysed forthe samples in the data set. For this report, the parameters examined generallyincluded major ions, metals, nutrients, pesticides and faecal bacteria when available.

Generally, the water quality of groundwater samples was found to be excellent. Therewere only isolated cases where the results exceeded drinking water guidelines. However, nitrogen levels in groundwater continue to be a concern both for drinkingwater in a low percentage of cases, and to a greater extent for nutrient enrichment ofsurface water bodies into which the groundwater flows. The metals content ofgroundwater was largely determined by natural bedrock conditions and almost all fellwithin drinking water guidelines. Most pesticide results have been published previouslyin other reports and these are briefly reviewed in this report. A small percentage of theanalyses had detectable concentrations and none exceeded drinking water guidelines.

Fresh surface water was found to be influenced by land use activities to varyingdegrees. Where these influences are not large, the water was generally cool and welloxygenated as is typical for PEI. However, where the influence of land use was moreevident, a trend of increasing nitrogen concentrations observed in all three stations witha 20-30 year period of record. Turbidity measurements also underline the connectionbetween water quality and land use with higher values in developed watersheds. Elevated faecal bacterial levels were noted in some locations with the levels for primarycontact being exceeded at several sites. Pesticides were commonly detected inconcentrations below aquatic life guidelines. For the most part, metals were notobserved at levels of concern, however elevated values for some metals have beenoccasionally recorded at many of the stations.

Estuarine water quality tended to be relatively good with some influences of land usebeing observed. Low dissolved oxygen levels were observed in several areas and are


ii

likely indicative of excessive nutrient input. Long-term trends in phosphorus suggestthat there have been increases. Given that the trophic status of PEI estuaries may bephosphorus limited, this implies a possible increase in productivity, suggesting thateutrophic problems may be worsening.


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Table of Contents

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Current Framework for Water Quality Monitoring in P.E.I. . . . . . . . . . . . 11.2 Water Resources Issues on Prince Edward Island . . . . . . . . . . . . . . . . . 2

2 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52.1 History of water quality sampling on P.E.I. . . . . . . . . . . . . . . . . . . . . . . . 52.2 Current Network Design & Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.3 Data Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3 Water Quality Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113.1 Physical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123.2 Major Ion Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.3 Nutrients / Chlorophyll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.4 Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303.5 Pesticides and selected other organic chemicals . . . . . . . . . . . . . . . . . 383.6 Faecal Coliform Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

4 Discussion and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514.1 Key Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514.2 Temporal Trends in Water Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534.3 Limitations of existing data collection network and recommendations for

further work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

5 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Appendix 1 Annex Water Quality Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Appendix 2 Historical Water Quality Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63


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List of Figures

1 Historical water quality stations (1961 - 1997). . . . . . . . . . . . . . . . . . . . . . . . . . 52 Monitored watersheds in the current water annex network. . . . . . . . . . . . . . . . . 73 Period of record for stations in the current network. . . . . . . . . . . . . . . . . . . . . . 84 Long term trend in pH in the Dunk River (PE01CB0001) . . . . . . . . . . . . . . . . . 135 Long term trend in conductivity in the Dunk River (PE01CB0001) . . . . . . . . . . 146 Seasonal dissolved oxygen trends in fresh water. . . . . . . . . . . . . . . . . . . . . . . 157 Seasonal dissolved oxygen trends in estuarine water. . . . . . . . . . . . . . . . . . . 158 Seasonal suspended solids trends in fresh water. . . . . . . . . . . . . . . . . . . . . . . 169 Long term trend in alkalinity in the Dunk River (PE01CB0001). . . . . . . . . . . . 1910 Long term trend in calcium in the Dunk River (PE01CB0001). . . . . . . . . . . . . 1911 Long term trend in magnesium in the Dunk River (PE01CB0001). . . . . . . . . . 1912 Seasonal trend in freshwater alkalinity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2013 Seasonal trend in freshwater calcium concentrations. . . . . . . . . . . . . . . . . . . . 2014 Seasonal freshwater nitrate trends. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2515 Seasonal trends in freshwater total nitrogen concentration. . . . . . . . . . . . . . . 2516 Long term trends in total nitrogen in the Mill, Dunk and Morell Rivers. . . . . . . 2517 Long term trends in nitrate in the Mill, Dunk and Morell Rivers. . . . . . . . . . . . . 2518 Long term trends in total phosphorus in the Mill, Dunk and Morell Rivers. . . . 2719 Long term trends in total phosphorus in the Mill, West and Montague River

estuaries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2820 Seasonal trends in freshwater chlorophyll concentrations. . . . . . . . . . . . . . . . 2921 Seasonal trends in estuarine chlorophyll concentrations. . . . . . . . . . . . . . . . . 2922 Relationship between total iron and turbidity. . . . . . . . . . . . . . . . . . . . . . . . . . 3723 Seasonal trends in freshwater faecal coliform concentrations. . . . . . . . . . . . . 4924 Seasonal trends in estuarine faecal coliform concentrations. . . . . . . . . . . . . . 50


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List of Tables

1 P.E.I. Estuaries with Eutrophic Symptoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Parameters Analysed for the Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Major Ion Chemistry of Fresh Waters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 Major Ion Chemistry of Estuarine Waters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Metal Concentrations in Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 Metal Concentrations in Fresh Surface Water . . . . . . . . . . . . . . . . . . . . . . . . . 327 Envirodat Results for Pesticide Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 Faecal Coliform Concentrations At Fresh Water Stations . . . . . . . . . . . . . . . . 489 Faecal Coliform Concentrations At Estuarine Water Stations. . . . . . . . . . . . . 50


1

1 Introduction

This report is intended to provide anoverview of the current state of theProvince’s groundwater, fresh surfacewater and estuarine resources, as well ashighlight any notable changes in waterquality over the available period of record.Although water quality data has beencollected in the Province since at least theearly 1960's, an interpretive reportsummarizing the key implications of thisdata has not been released since 1978,when Environment Canada published the“Water Quality Interpretive Report, PrinceEdward Island, 1961-1973 (Inland WatersDirectorate, Water Quality Branch, 1978).While the primary focus of this report ison data collected from stationscomprising the “Water Quality Network”and its predecessors, data from othersources has been drawn upon selectively,where such information helps provide amore comprehensive setting or context inwhich to discuss data from the “Network”.

In order to adequately assess temporaltrends in water quality, this reportexamines the full period of recordavailable, and thus overlaps with the 1978Interpretive Report. To avoidunnecessary duplication however,observations that may be pertinent only tothe earlier period of record are notdiscussed.

This chapter provides a brief overview ofthe framework under which water qualitymonitoring is currently conducted, ageneral description of the key waterresources issues in the Province, and theintended scope of the report.

1.1 Current Framework forWater Quality Monitoring inP.E.I.

The Province of P.E.I. and EnvironmentCanada have maintained variouscooperative agreements for water relatedenvironmental monitoring and researchover the past several decades. The mostrecent framework for this activity fallsunder the umbrella of the Canada-P.E.I.Water Annex to the Federal ProvincialFramework Agreement For EnvironmentalCooperation in Atlantic Canada. This“Water Annex” provides the basicmanagement structure for the oversight ofall cooperative water related activitiesconducted in the Province. Under theAnnex, long term water quantity andwater quality monitoring are conductedunder the Ecosystem Monitoring Programcomponent, while shorter term studies orprograms are conducted under the WaterManagement Initiatives program area.

This division in program areas is intendedto reflect the need for far sighted, longterm monitoring of basic water data atselected sites on the one hand, whileproviding sufficient flexibility to addressmore specific water issues on an asneeded basis, and with project structuresdesigned to meet the specific datarequirements dictated by the nature of theissue being investigated. Thus theassessment of long term water qualitydata, such as presented in this report issupported by the existence of theEcosystem Monitoring program and itspreceding equivalents, while morefocused work such as the relationshipbetween run-off and pesticide levels insurface waters can be conducted with aunique project design developed to meetspecific research needs.


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1.2 Water Resources Issues onPrince Edward Island

On a small Island Province, water, like theweather, is never far from one’s thoughts,and indeed much of our well-beingdepends on the status of theserenewable, yet finite, resources. Becauseof the physiography of the Province, largefresh surface water bodies are absent,with few lakes, and rivers which for muchof their length are brackish.

While the Island has the luxury ofsubstantial groundwater resources tomeet many of our human fresh waterneeds, the fresh water streams andponds of our province must still sustain ahost of other functions as aquatic habitatand as part of the broader ecosystem thatis home to our wildlife. In addition, thesame features that explain theabundance of our groundwater resourcesalso render them vulnerable tocontamination, and once tainted,remediation is often not possible.

Even in our estuaries, which support suchbiological abundance and are thebackbone of a growing part of ourfisheries sector, water quality determinesthe extent to which this resourcecontributes to our economy and overallwellbeing. In short, P.E.I. has been wellendowed with a resource that can makea substantial contribution to our lives, butwater quality issues dictate the limitationsto our use of these resources.

Until relatively recently, most water issuestended to be regarded as more or lessindependent of one another. Today, amore holistic view of the environmentprevails, and the interconnections

between groundwater, fresh surfacewater and estuarine environments isbetter appreciated. With this trend is thegrowing realization that the cause andsolution to many of our more pressingenvironmental problems cannot be solvedin isolation, but must be addressed in abroader context. As an example, thegrowing incidence of eutrophic conditionsin our estuarine waters involvesgroundwater and surface water qualityissues, and ultimately the impact of landuse on these resources. This in turnreflects the fact that groundwaterdischarge accounts for some 60 to 70%of fresh surface water flows on the Island,and at some critical periods is thedominant source of water and thusprimary influence on surface waterquality. The current water qualitynetwork, and its integration with waterquantity stations, is a reflection of thisinterconnectedness, and the need for abroader view of the environment.

Key areas of concern that have persistedover the years include soil erosion, andthe resulting siltation of streams andestuaries, elevated nitrate concentrationsin groundwater and surface waters,bacterial contamination of shellfishharvesting areas, and the occurrence ofpesticide residues in groundwater andsurface waters. These water qualityissues have been discussed at variouslengths in previous publications such as“Cultivating Island Solutions” (RoundTable on Resource Land Use andStewardship, 1997); “Water on PrinceEdward Island - Understanding theresource, knowing the issues” (P.E.I.Dept. of Fisheries and Environment andEnvironment Canada, 1996); and“Evaluation and Planning of WaterRelated Monitoring Networks on Prince


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Edward Island” (Environment Canada -Prince Edward Island Dept. of theEnvironment, 1991), and are summarizedvery briefly below.

For several decades, the loss of theIsland’s soils and the resulting damage toagricultural lands and to aquatic habitathave been recognized as a majorproblem. While considerable progresshas been made in the developmenttechniques to minimize soil erosion byagriculture, forestry and highwayconstruction activities, much workremains to be done, particularly withrespect to the wide spread adoption ofeffective erosion control measures. Longterm monitoring of sediment in ouraquatic systems may help us measureour progress as these efforts continue,and help focus our efforts on areas ofgreatest priority.

The occurrence of elevated nitrate levelsin groundwater, especially in areas ofintensive cultivation, is common in manyagricultural areas around the world.While the situation for P.E.I. groundwaterappears not to be critical for drinkingwater purposes, nitrate levels clearlydepart from “natural levels” often by asmuch as 3-4 times assumed backgroundlevels, and in some heavily cultivatedwatersheds nitrate levels in water from asmany as 6 to 7% of wells exceeds therecommended guideline level (Somers,1998; Swain, 1995).

Equally important, is the influence ofgroundwater quality on the level ofnutrients in fresh and estuarine portionsof surface water bodies. As noted above,baseflow in Island streams comprises ahigh proportion of total discharge, andnitrate concentrations well below levels of

concern for drinking water quality are ofser ious concern in estuar ineenvironments, where over-enrichmentwith nutrients, principally nitrogen andphosphorous, can stimulate excessprimary productivity, leading to eutrophicconditions in estuarine environments.

Currently, a significant number of Islandestuaries exhibit symptoms ofeutrophication that have been linked toland use and nutrient enrichment(Thompson, 1998). Table 1 lists some ofthe estuaries for which impacts havebeen reported, and the associatedsymptoms.

Bacteria associated with runoff fromagricultural areas, urban areas andwastewater effluent, while not causingdirect environmental problems, haveindirect implications for the economy ofthe Island. The principal impact is felt inthe shellfish industry, where excessivelevels of faecal coliform bacteria renderlarge portions of the prime shellfishproducing areas of the Province unfit forsale directly to the consumer because ofthe risk to public health. In spite of fairlycomprehensive wastewater treatmentprovisions in the Province, non-pointsources of bacteria, particularly impactsof livestock on surface waters, have directand substantial economic implications forthe Province (P. Lane and Associates,1991).

The presence of pesticides in water havebeen a particularly controversialenvironmental issue over the past severaldecades. Several recent fish kills in thewestern portion of the Province appear tobe related to typical pesticide application.Analyses of water samples from thesefresh water systems have indicated the


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Table 1 P.E.I. Estuaries with Eutrophic Symptoms

Estuary Observed Conditions

Barbara Weit River Anoxic

Boughton River Depressed oxygen upper estuary

Brackley Bay Anoxic

Hunter River Anoxic

Mill River Anoxic

Morell River Anoxic

Pinette River Anoxic

Souris River Anoxic

Southwest River Anoxic

Stanley River Anoxic

Trout River (New London Bay) Anoxic

Vernon River Anoxic

Wheatley River Anoxic

presence of a variety of pest controlproducts, but at levels which would not beexpected to be lethal for fish.Nonetheless, it has proved very difficult tocollect samples at the critical periodimmediately preceding a fish kill, and thefull severity of pesticide contamination ofsurface waters is likely to beunderestimated by the results from thegrab samples collected to date.

The occurrence of pesticides ingroundwater has received considerableattention, although generally speaking,these compounds have not been foundfrequently in groundwater samples.Furthermore, with the exception of caseswhere the presence of pesticides can beattributed to a spill or other accidentalrelease, when detected, concentrations

have been very low, well below drinkingwater guideline values. While the resultsof pesticide analyses of groundwaters hasgenerally not shown cause for alarm, atleast one compound, hexazinone, isbeing found with disconcerting frequencyin some environments, notably in relationto blueberry cultivation.

Because agriculture plays such adominant role in the Province’s economyand landscape, it also has tended todominate the agenda in terms of waterquality. As a result, other potentialcontaminants which might be of moreinterest in more heavily industrializedareas have not been given the sameamount of attention. Nonetheless, otheranthropogenic activities have left someimprint on water quality, especially in


5

Figure 1 Historical water quality stations (1961 - 1997).

urban areas, where fuel spills, roadsalting and other commercial activitieshave impaired natural water quality.

2 Methodology

2.1 History of water qualitysampling on P.E.I.

Systematic water quality data collectionon P.E.I. began with the establishment ofthe International Hydrologic Decade (IHD)in the mid 1960's, and has evolved sincethen through various configurations inresponse to changing issues, fiscalresources, and general approaches toenvironmental monitoring. (See Figure 1.Historical Water Quality Stations, 1961-

1997.)

Some of this work has been designed asscreening surveys with extensiveparameters lists, whereas other studieshave focused on more in-depthinvestigations of specific parameters. Thisdata has been used to support variouswater management needs including “stateof the environment reporting”,development of national water qualityguidelines and priorization of researchneeds.

Much of the earlier work on water qualitywas driven by specific issues, andconducted under short term mandates toinvestigate specific phenomena such asthe occurrence and distribution of variousorganic chemicals, heavy metals, etc. As


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a result, the considerable sampling effortsdevoted to particular locations orparameters at one time are notnecessarily followed up in subsequentperiods of record. In assessing the datacovered in this report this has beenconsidered, otherwise a somewhatskewed view of overall results wouldemerge.

For example, while some stations haveshown a high frequency of detections fora particular pesticide, these results mayreflect the efforts of concentratedsampling over a short period of time, andmay not reflect overall water qualityconditions at that site over the period ofrecord, or at other stations across theIsland. Where possible, an attempt hasbeen made to account for these factors.

While groundwater sampling has beenconducted for a good portion of this time,such sampling typically was conducted onan ad hoc, issue driven basis, and as aconsequence long term records fromindividual stations are rare. Only sincethe adoption of an “index basin approach”developed in the early 1990's, have theseactivities been integrated with other waterquality monitoring efforts.

Established as Canada’s contribution tothe IHD, the National Water Qualitynetwork (1965-1974) saw four stationsestablished on P.E.I. At this time, thenetwork on P.E.I. was based ongeographic distribution and proximity tostream gauging stations. The IHDprogram was established to maintain awater quality and pollution evaluationnetwork.

By the early to mid-1970's the originalIHD network evolved into the National

Water Quality Monitoring Program. Builton the original IHD network, additionalstations were added on an issue drivenbasis. At the height of activity, 22 siteswere in operation representing the majorriver basins on the Island.

In 1978, as a result of changing Federalmandates, the network was cut to 3 siteson P.E.I., and continued operation underthe Atlantic Region Overview/LRTAPNetwork (1978-1991). Two of thesestations; Carruthers Brook on the MillRiver system and the Dunk River hadbeen continuously monitored since theIHD program was initiated in 1965, andthe third station on the Morrell had beenestablished in 1974.

In 1991 the Federal and Provincialgovernments undertook a major review ofall water related monitoring networks, andproposed for the first time, an integratedapproach to the collection andassessment of surface water andgroundwater quantity and quality data(Environment Canada / P.E.I. Dept. ofthe Environment, 1991). Under this basicpattern, with a strong focus on the“watershed” as the principle unit for study,groundwater and surface water qualitymonitoring continues to the present day.Also at this time, monitoring resumed inestuaries as part of this program. Whileestuaries were monitored under the IHDprogram, subsequent monitoring wascompleted by the province alone until1991.

At its inception, water quality samplingwas conducted under the Canada/P.E.I.Water Quality Monitoring Agreement. In1995, this agreement and others werereplaced by the Canada/P.E.I. WaterAnnex however the programs differ only


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MillRiver

Dunk River

Montague River

BearRiver

West River

Wilmot River

Figure 2 Monitored watersheds in the current water annex network.

in their administrative framework.

Under this arrangement, the Province &Canada jointly maintain a network ofwatersheds across the Island where longterm monitoring of groundwater andsurface water quantity and quality arecarried out. Although a total of 7 basinsaround the Island were originallyestablished, rationalization has reducedthe scale of the network to five basins;three “index basins” and two“management basins”.

2.2 Current Network Design &Operation

The network (Figure 2) now comprisesthree fully monitored watersheds where

groundwater observation wells andstream gauges continuously measure thequantity of water flowing through thewatersheds, and groundwater andsurface water quality monitoring stationswhere grab samples are collected on aroutine basis. These watersheds havebeen specifically selected to reflect therange of regional and physiographiccharacteristics of P.E.I., and are referredto as “Index Basins” (Mill, West and BearRivers). In addition, two otherwatersheds have been equipped withmonitoring stations dedicated to morespecific, shorter duration researchobjectives relating to groundwater andsurface water quantity and quality, andare designated as “Management Basins”(Dunk/Wilmot and Montague/ValleyfieldRivers). All stations are supported by an


8

PE01CA0001PE01CA0015PE01CA0043PE01CA0044PE01CA0045PE01CA0046PE01CA0047PE01CA0048PE01CB0001PE01CB0143PE01CC0010PE01CC0092PE01CC0113PE01CC0213PE01CC0214PE01CC0220PE01CD0050PE01CE0096PE01CE0099PE01CE0100PE01CE0101PE01CE0102PE01CE0103PE01CE0104

Stat

ion

1960 1970 1980 1990 2000Year

Figure 3 Period of record for stationsin the current network.

Island wide network of precipitationstations operated by EnvironmentCanada.

The current agreement includes 23sampling sites of which 9 are inlandstreams and rivers, 9 are estuarinesampling stations and 5 are groundwatersites. Figure 3 shows the period of recordfor the current long term water qualitystations. Sampling sites maintainedunder the Water Annex are sampled from6 to 8 times per year. Table 2 lists theparameters currently measured at“annex” stations.

2.3 Data Assessment

The data set on which this report is basedis a subset of a larger Atlantic regiondatabase maintained by EnvironmentCanada called Envirodat. The majority ofthe analyses in this database have beenanalysed by Environment Canada or itspartners. These analyses werecompleted using standard methodsadopted by Environment Canada and theP.E.I. Dept of Technology andEnvironment. The data extractions fromEnvirodat for this report generallyselected data collected in P.E.I. thatrepresent ambient environmentalconditions. That is, data that were part ofexperimental manipulations or effluentdata or other data not representative ofthe environment for similar reasons werespecifically avoided.

The storage of data on Envirodat is veryspecific with respect to the namingconvention for analyses that are similarbut not exactly the same. When everthere is a slight difference in the analyticalmethodology, a different parameter nameis utilized. For this report, it is more

important to assemble general long-termdata sets than to be able to determineminute differences in methods.Whenever possible, parameters ofessentially the same analysis weregrouped together. As there is somedanger in this approach of grouping datatogether to produce an erroneousconclusion, considerable care was takento examine the individual parametersseparately prior to combining for obviousinconsistencies. The number of rawparameters originally extracted fromEnvirodat was extensive, exceedingseveral hundred. Of these, approximately260 were consolidated to ~90. As theunits were sometimes different betweenparameters, care was taken to convertparameters with differing units to thesame units prior to consolidation. A tableoutlining the actual Envirodat parametersthat were combined to form the data setfor this report is available from the Dept.of Technology and Environment. Therewere number of parameters that were notincluded in the analysis. This wasgenerally because either the parameterhad too few values or was not ofsignificant interest on P.E.I.. Also, therewere a number of metals that were


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Table 2 Parameters Analysed for the Network

Parameter Groundwater Fresh surfacewater

Estuarinewater

Aluminum (total) � �

Alkalinity (total) � �

Ammonium (NH4+NH3) �

Arsenic (total) � �

Dissolved Organic Carbon � �

Calcium (dissolved) � �

Cadmium (total) � �

Chlorophyll a � �

Chloride (dissolved) � �

Cobalt (total) � �

Colour � �

Chromium (total) � �

Copper (total) � �

Dissolved oxygen � �

Iron (total) � �

Faecal Coliforms � � �

Lead (total) � �

Potassium (dissolved) � �

Magnesium (dissolved) � �

Manganese (total) � �

Nitrogen (total) � �

Sodium (dissolved) � �

Nickel (total) � �

Nitrate+Nitrite Nitrogen � � �

Phosphorous (total) � �


Table 2 Parameters Analysed for the Network

Parameter Groundwater Fresh surfacewater

Estuarinewater

10

pH � � �

Salinity �

Sulphate (dissolved) � �

Specific Conductance � � �

Suspended Solids � �

Temperature � �

Total Coliforms �

Turbidity � �

Zinc (total) � �

analysed as both an extractable and atotal analysis. With the exception ofmercury where a total analysis was notavailable, only total analyses wereselected for this report. This wasprimarily because the various CanadianCouncil of Ministers of the Environment(CCME) water quality guidelinesreference values for analyses of totalmetals.

Due to the varying nature of the analyticalmethods, the detection limits oftendiffered for the various parameters thatwere combined. To address this problem,for the purposes of calculating statistics,analyses with a result of less thandetection limit were converted to zeros.As a result, all average statistics reportedin the main body of this report should beconsidered as slightly conservative. Inmost circumstances, this conservativetendency is so minor as to be completelynegligible. This is not the case forpesticides where the frequency of

non-detects is very high. In these cases,in lieu of the average concentration, thefrequency of detection is reported as wellas the maximum concentration.

Many stations in the data set weresampled on a few occasions and a fewstations were sampled hundreds of times.As a result, without weighting the data,average statistics would be heavilyweighted towards the water quality at thestations that were sampled more often.In order to properly weight the data whencalculating overall averages, averageswere first calculated for each station andthen the station averages were averagedto determine a global average. Readersshould note that when reported, standarddeviations thus show the variability of thestation averages, not the variability ofindividual samples. As this methodologydoes not provide any information on theextremes of the data set, the rangereported is the actual minimum andmaximum analysis values to impart some


11

information on the outliers in the data set.

A number of the stations that were listedas freshwater were clearly influenced bytidal conditions as indicated by examiningthe location of the station and the generalionic make-up of the water. Thesestations were omitted from thecalculations for freshwater so as toensure that the resulting statistics trulyrepresented only freshwater conditions.

Only a few stations had extensive recordsof analyses that span the severaldecades included in this report. Becauseof this simple limitation, much of thelong-term trend information reported inthe data set originates from these sites.They are the Dunk River (PE01CB0001;1966 - present), the Carruthers Brook onthe Mill River (PE01CA0001; 1966 -present) and the Morell River(PE01CD0003; 1972 - 1995).

There are a number of scatter plots in thereport with scatter plot lines displayed onthe graph. These lines were generatedby Systat 7.0 using the LOWESS optionwith the tension set to 0.5. The choice ofthis particular option for this purpose wasdue to its ability to determine a scatterplot line and not be unduly affected by theodd outlier.

Because virtually all potable water inP.E.I. comes from groundwater sources,groundwater quality has been assessedp r in c i p a l l y a c co rd ing to t herecommendations in the Guidelines forCanadian Drinking Water Quality,published by Health Canada. For surfacewater stat ions, the CanadianEnvironmental Water Quality Guidelinespublished by CCME with respect to theprotection of aquatic life have been used

to assess water quality. CCME does nothave a large set of guidelines estuarineenvironments, but where it appearsrelevant, the equivalent fresh waterguideline has been used as a basis forevaluation. In a few cases, otherappropriate national guidelines have beenutilized which are noted in the text whenused. Where a national guideline doesnot exist and where there are suspectedadverse implications associated with thepresence of a compound in a particularmedia, alternate guidelines may bequoted from other jurisdictions.

3 Water Quality Results

The discussion of results for samplescollected from the water quality network isorganized by the nature of the parametermeasured, and for the most partcombines results and observations fromgroundwater, surface water and estuarinesampling stations. This is in recognitionthat all three media are intimately relatedon P.E.I. and many of the influences onwater quality are common or at leastloosely related. While the focus of thereport is on results from the network, fromtime to time reference is made to relevantobservations from other work.

This chapter begins with a discussion ofphysical characteristics of natural waters,followed by a discussion of the majorinorganic constituents which determinethe overall characteristics of these waters.Additional parameters are discussedunder the headings of nutrients, metals,pesticides and other organic chemicalsand bacteria.

Although one of the key aims of thisreport is to examine temporal changes in


12

water quality, the design and changes tothe network as it has evolved over theyears and the resulting period of recordfor many stations limits the ability to drawfirm conclusions in many of these areas.Where possible, it has been indicatedwhether the distribution of a particularparameter or group of parameters hasremained stable over the period of recordor not. Where temporal trends of interestare noted they are discussed more fully inChapter 4.

3.1 Physical Characteristics

There are a variety of measurementsmade on water samples that looselycharacterize the physical properties of theaquatic environment, or provide indirectinformation on the chemical compositionof these waters. For simplicity, these arecollectively grouped here under thecategory “physical characteristics”,recognizing that some of these measurescould be more correctly referred to aschemical parameters. Accordingly, theparameters pH, temperature, conductivity,dissolved oxygen, turbidity and totalsuspended solids are discussed.

3.1.1 pH

The measurement of pH is used toindicate whether a solution is acidic oralkaline. A solution that is considered tobe neutral has a pH of 7.0. The pH ofwaters may provide useful clues to theevolutionary history of natural waters, aswell as indicating a variety ofanthropogenic influences. Over the pastfew decades, one of the key interests inthe pH of natural waters in AtlanticCanada has been the influence of acid

precipitation. pH also sheds light on thebuffering capacity of soils and aquifermaterials and can act as a finger print indistinguishing between relatively newnear surface waters and oldergroundwaters which reflect a longerperiod of chemical interaction with aquifermaterials. Thus, changes in pH canreflect the progressive reactions betweengroundwater and aquifer materials as ittravels throughout the groundwater flowsystem.

Groundwater samples from the networkhad a mean pH of 7.7 and all but onesample (representing 0.3% of results) fellwithin the pH range of 6.5 to 8.5recommended in the Guidelines forCanadian Drinking Water Quality.Although the period of record forgroundwater stations is limited, notemporal trend is indicated by the data.Given the strong buffering capacity ofthese waters as a result of relatively highalkalinity, it is not surprising that nochanges are apparent.

While pH values for fresh surface watersexhibit a slightly greater variability thanobserved for groundwater sources, theyare still relatively uniform across theProvince and fall in the same range, witha mean pH of 7.5. The CCME guidelinesfor the protection of aquatic life suggest apH range of 6.5-9.0 and only 2.7% felloutside this range, with maximum andminimum values of 9.1 and 4.2respectively. In the majority of thesecases, pH was below 6.5 although in afew cases, pH exceeded 9.0.

The data collected to date indicate atrend of increasing pH values for freshsurface waters, with a gradual increase ofapproximately 0.2-0.4 pH units over the


13

Figure 4 Long term trend in pH in theDunk River (PE01CB0001)

25-30 year period of record (Figure 4).The most notable change is in the DunkRiver, where pH has increased byapproximately 0.4 pH units over the past30 years . A decrease in the acidity ofprecipitation and an improvement inprecipitation water quality has been notedin the Atlantic Region over the past 20years (Environment Canada, 1998). Theobserved increase in pH in Island freshwater bodies may be a reflection of anoverall improvement in precipitationquality in the region.

Estuarine waters have pH values whichrange from 4.6-9.4 with a mean pH valueof 7.7. No long term trends are apparentin data from these stations.

3.1.2 Temperature

Measurements of temperature areroutinely taken when samples arecollected either as part of the network orfor other programs. As it is unclear thatthe ground water temperature recordsrepresent the temperature at depth in theground as opposed to the temperature inthe water distribution system, groundwater temperature records have not beenassessed in this report.

In the surface water the primary trends ofinterest are normal seasonal andlong-term changes. While factors such asriparian zone cover vegetation,impoundments and long term airtemperature trends all could be expectedto influence water temperatures,long-term trends are not evident in thedata set.

It is not clear that the surface watershould mirror the well known increases in

air temperature. The variability intemperature between stations due to theinfluence of other factors such as theprevalence of ponds and springs couldobscure any subtle long term changes.The infrequent collection of temperaturerecords could further preclude thedetection of any change in the surfacewater temperature record.

Seasonally however, temperatures varywidely. As would be expected, maximumsfor fresh and estuarine waters occur inJuly and August respectively. Averagesummer and winter freshwatertemperatures are approximately 15 and1°C respectively. Average summer andwinter estuarine temperatures areapproximately 18 and 0°C respectively.

3.1.3 Conductivity

Conductivity, a measure of the ability ofan aqueous solution to carry an electricalcharge, provides a useful surrogate formeasures of total dissolved solids orsalinity, and is a practical field method forpreliminary assessment of water quality.


14

1960 1970 1980 1990 2000Year

0

100

200

300

Con

duct

ivity

(µsi

e/cm

)

Figure 5 Long term trend inconductivity in the Dunk River (PE01CB0001)

Groundwater samples for the provincehad a mean specific conductivity of 329�S/cm while fresh waters had a meanspecific conductivity of 200 �S/cm. Thehigher average values for groundwaters isconsistent with the longer residence timefor groundwater, (and thus the greatercontact time with reactive soil and aquifermaterials) as compared with surfacewater. In fact, the relatively high valuesfor fresh surface waters underline theimportance of groundwater discharge indetermining surface water quality onP.E.I.

Overall conductivity levels forgroundwaters and most fresh surfacewaters have remained stable over thelimited period of record for these stations.An exception to this case is seen forsurface water stations on the Dunk River.Conductivity values here have risen byapproximately 50 �S/cm over the past 30years (Figure 5). This increase correlateswith an increase in calcium, magnesiumand alkalinity, discussed later in Section3.2 of the report.

3.1.4 Dissolved Oxygen

Dissolved oxygen, while strictly speakinga chemical parameter, is discussed herebecause it fits the general role as anindicator of a variety of physical,biological and chemical processes in theaquatic environment. The availability ofdissolved oxygen is important for mostforms of life and the CCME guidelines forthe protection of aquatic life recommendoxygen concentrations of at least 9.5 mg/lfor the protection of early life stages ofaquatic life, based on the premise thatthis level is set to maintain a level of atleast 6.5 mg/l of dissolved oxygen instream sediments for salmonoidspawning habitat. The guideline for otherlife stages is 6.5 mg/l.

The mean concentrations of dissolvedoxygen observed in freshwater streams is12.35 mg/l, with nearly 95% of samplesmeeting or exceeding the 9.5 mg/lguideline for protection of early life stagesof aquatic organisms. Forty-two of 748(5.6%) samples were below the 9.5 mg/lguideline and 2 of 748 (0.3%) were belowthe 6.5 mg/l guideline for the protection ofaquatic life. The minimum level of 2.3mg/l was recorded on the West Branch ofthe Morell River at station PE01CD0022.

Dissolved oxygen concentrations for thefresh surface waters have remainedrelatively stable over the past 25 yearshowever seasonal patterns are typicallyobserved, with decreasing levelsoccurring throughout the warmer summermonths and increased concentrations inthe autumn and winter. This seasonalvariation is more pronounced in theestuarine data than in the fresh waterdata (Figures 6 and 7).


15

Figure 6 Seasonal dissolved oxygentrends in fresh water. Dashed lines indicateaquatic life guidelines.

1 3 5 7 9 11 13Month

0

5

10

15

Dis

solv

ed O

xyge

n (m

g /l)

Figure 7 Seasonal dissolved oxygentrends in estuarine water.

The mean d isso lved oxygenconcentration for estuarine samples is 9.9mg/l, however low dissolved oxygenconcentrations have been recorded for anumber of estuaries. Dissolved oxygenvalues below 3.0 mg/l were recorded forsites PE01CA0004 and PE01CA0005, onthe Kildare River Estuary; PE01CA0047on the Mill River and PE01CA0007 on theHuntley River Estuary, with a minimumvalue of 0.4 mg/l.

These low concentrations of dissolvedoxygen are a serious concern for aquaticlife, and point to significant problems insome estuaries of the Province. Althoughaverage concentrations of this parameterare generally high and are fairlyconsistent across the Island most of thetime, short term periods of low dissolvedoxygen concentrations are sufficient tocause significant damage to aquaticcommunities. While this data set doesnot indicate severe problems, other workhas demonstrated low dissolved oxygenconcentrations in a number of upperestuarine areas on P.E.I.

3.1.5 Turbidity

Turbidity is a measure of water clarity,based on the transmission of light throughthe water column. While turbidity is animportant parameter for drinking watertreatment plants exploiting surface watersources, where all potable water comesfrom groundwater on P.E.I., its primesignificance here is the implications forthe health of aquatic habitat.

The mean turbidity for fresh surfacewaters on P.E.I. is 3.0 Jackson TurbidityUnit (JTU), with values ranging up to asmuch as 700 JTU, recorded at stationPE01CB0001 on the Dunk River. Albertaand Saskatchewan have set turbidityguidelines, for the protection of aquaticlife, that allow a maximum increase of 25JTU above background levels. Therehave been no background levelsestablished for turbidity in P.E.I. streams,and comparison with these recommendedlevels is not possible at this time. Inaddition, care must be exercisedinterpreting this data due to the nature ofgrab sample measurements. Forparameters such as turbidity, it is


16

1 3 5 7 9 11 13Month

1

10

100

Susp

ende

d So

lids

(mg/

l)

Figure 8 Seasonal suspended solidstrends in fresh water.

expected that measurements under dryweather conditions would be much lowerthan measurements under wet weatherconditions in watersheds where there issignificant soil erosion as occurs in anumber of P.E.I. watersheds. No attemptwas made for this report to determinewhether wet weather events wereadequately monitored in the data set.With this type of program andparameters, the calculated average of abiased data set normally underestimatesthe true average for the parameter. It isalso possible that the maximummeasurement does not fairly representconditions that commonly occur underwet weather conditions.

Turbidity levels show a significant degreeof spatial variability across the Island withconcentrations generally being correlatedto land use practices, and the potentialfor significant soil losses via erosion. Asan example, the mean value ofmeasurements from the Dunk River, in aregion of intense cultivation, is 9.7 JTU,while the mean value from the Bear River,a relatively non-impacted area, is 0.56JTU. Long-term data for turbidity doesnot indicate any trend over the period ofrecord, and does not appear to show anyseasonal variability. Experience hasshown that heavy runoff events mayoccur at any time of the year. In addition,data from grab sampling, may notnecessarily reflect the influence of stormevents which would be expected tocorrelate with higher turbidities.

3.1.6 Total Suspended Solids

Total suspended solids are ameasurement of all material suspendedwithin the water column, and like turbidity

this parameter is generally important inthe assessment of the health of aquatichabitat. Soil erosion, and the resultingsiltation in Island streams has beenidentified as one of the most pressingenvironmental issues on the Island.CCME guidelines for the protection ofaquatic life recommend that addedsuspended solids should not exceed 10mg/l when background suspended solidsconcentrations are equal to or less than100 mg/l, and should not exceed 10% ofbackground levels when backgroundlevels exceed 100 mg/l (CCME, 1987).

Mean suspended solids concentrations of4.5 mg/l were recorded for the surfacewater stations, with only one sampleexceeding 100 mg/l. However, theseresults are not likely to provide anaccurate representation of suspendedsediment, as the data is derived fromgrab samples that may not capture theepisodic, short term transport ofsediments that one would expect to beassociated with heavy runoff events.With the limited amount of data availableit can be demonstrated that suspendedsediment concentrations follow aseasonal trend (Figure 8). Averageconcentrations drop from approximately 4


17

to 2 mg/l from the summer through thefall.

Data collection for this parameter beganin the early 1990s and because the dataset contains no long term data uponwhich to determine background levels forsuspended solids, a comparison withthese recommendations is not possible atthis time.

3.2 Major Ion Chemistry

The general chemical characteristics ofmost natural waters are determined bythe relative and absolute concentrationsof the major cations and anions present insolution. These characteristics are in turndetermined largely by the “history” of thewater, and reflect the nature ofprecipitation in the area, the materials thewater is in contact with and residencetime of the water as it flows through thelocal environment. These major ioncharacteristics can be used to definegeneral “water types”, and can facilitatediscussion of the broad characteristics ofnatural waters and trends in water quality.Described below are observations on themajor ion chemistry of the Province’sfresh and estuarine waters.

Fresh Waters

On P.E.I., groundwaters and freshsurface waters share generally similarmajor element characteristics, and are ofa "calcium - bicarbonate" or "calcium -magnesium - bicarbonate" type, reflectingthe influence of carbonate minerals inlocal soils and bedrock. Generallyspeaking, waters in the eastern andcentral portions of the Island are calcium-

magnesium bicarbonate waters, resultingfrom the dissolution of dolomitic cementin soils and bedrock. Further west,calcium - bicarbonate waters dominate,presumably reflecting the importance ofcalcite as opposed to dolomite as acementing agent in local bedrock. Whilethe relative abundance of these ions issimilar in fresh and groundwater, thelatter normally have higher total dissolvedsolids because of their longer residencetime in contact with the soil and bedrockwhich determines their character.However, because of the significantvolumetric contribution of groundwater tosurface water systems, the differences intotal dissolved solids are not always large.Groundwaters are normally hard to veryhard and have neutral to slightly alkalinepH’s. Surface waters are normallysomewhat softer and exhibit lower totaldissolved solids than groundwaters,although they also exhibit the sameneutral to slightly alkaline pH.

Two other water types, both associatedwith groundwater, are known to occur onP.E.I., but are not represented by any ofthe sampling stations upon which thisreport is based. They are mentionedbriefly because of their localizedimportance, although their geographicdistribution is limited .

The first are "sodium - chloride" typegroundwaters where fresh groundwater ismixed with marine water, with resultingbrackish to saline groundwaters occurringlocally in some coastal aquifers. Thesecond are sodium bicarbonate watersthat are known to occur at depth in someregional flow systems, and more rarely inlocalized discharge regions of thesesystems in some areas of the province.Characterized by high sodium and total


18

Table 3 Major Ion Chemistry of Fresh Waters

Parameter Groundwater Surface Water

mean std. dev.

range mean std. dev.

range

calcium mg/l 37.7 16.2 LD - 137 21.9 10.7 0.5 - 57

magnesium mg/l 12.6 7.9 LD - 72 6.9 4.3 0.5 - 31

sodium mg/l 10.2 8.1 1.4 - 165 6.2 2.7 1 - 32

potassium mg/l 1.7 1.5 0.09 - 14 1.3 0.5 LD - 10

alkalinity* mg/l 128.3 41.7 6.7 - 488 67.9 26.8 3.6 - 203

chloride mg/l 21.9 22.4 0.7 - 711.7 12.1 6.2 0.1 - 62

fluoride mg/l 0.053 0.046 LD - 0.72 0.026 0.025 LD - 0.72

sulphate mg/l 9.0 4.7 LD - 41.7 6.5 4.1 LD - 39.8

conductivity** �S/cm 329 115 30.1 - 1680 200 121 18.8 - 1100

* Alkalinity is generally assumed to reflect the activity of carbonate speciesin most natural waters and is used as a proxy for bicarbonateconcentration in this discussion.

** Conductivity values are used here as a proxy for total dissolved solids.

dissolved solids but low chloride levelsand hardness, these waters are oftenreferred to as “naturally softened” watersand their chemical characteristics reflection exchange processes betweengroundwater and clay minerals in theaquifer. Because of the localized natureof these features, and their lack ofrepresentation in the data base uponwhich this work is based, these watertypes are not discussed further in thisreport. Table 3 describes the generalrange of major ion compositions for P.E.I.groundwater and fresh surface waters.The mean values reported are in fact themean of mean values for individualstations, and standard deviationscalculated for these mean station valuesas well. These are intended to provide an

indication of the average characteristics,and variability of fresh water stationsacross the Island. The range reportedreflects the span of all analyses from allstations for that parameter.

With the exception of the calcium:magnesium ratios noted above, therelative abundance of major ions ingroundwater samples is relativelyconsistent across the Province, and therange of absolute concentrations for eachof these constituents is likely to reflectresidence time of water in the aquifer.This in turn can be expected to vary fromsite to site as a result of factors such asposition within the groundwater flowsystem and well construction. Althoughthe period of record for groundwater


19

1960 1970 1980 1990 2000Year

0

10

20

30

40

50

60

70

80

90

100

Alka

linity

(mg/

l)

Figure 9 Long term trend in alkalinityin the Dunk River (PE01CB0001).

1960 1970 1980 1990 2000Year

0

10

20

30

40

50

60

70

80

Cal

cium

(mg/

l)

Figure 10 Long term trend in calcium inthe Dunk River (PE01CB0001).

1960 1970 1980 1990 2000Year

0

1

2

3

4

5

6

7

8

9

Mag

nesi

um (m

g/l)

Figure 11 Long term trend inmagnesium in the Dunk River (PE01CB0001).

samples is considerably shorter than forsome surface water stations, no temporaltrends are apparent in the major ioncomposition of groundwaters representedin the data set, and all parameters arewell within the range consideredacceptable for drinking water quality.

As is illustrated in Table 3, the relativeproportions of major ions for fresh surfacewaters of the Province are generallysimilar to groundwater, but occur inslightly lower concentrations. Unlikegroundwater, however, some temporaltrends in surface water quality have beenobserved at stations with a long term

period of record. Samples from the Dunk,Mill and Morell rivers, exhibit a subtle, butsignificant increase in alkalinity, calciumand magnesium, the ions constituting thebulk of dissolved constituents in thesewaters. These increases have also beenaccompanied by similar increases inconductivity in the Dunk River, but havenot been observed in the Mill or MorellRivers. Figures 9 through 11 illustratethese trends in the Dunk River data. Noclear explanation of this trend is apparentat this time.

S l igh t i n c re ases in ch lo r ideconcentrations have also been observedin samples from the Dunk and MorellRivers, and may be related to road saltapplication within these watersheds,however the significance of this weaktrend is unknown at this point.

Long term surface water data for theDunk, Mill and Morell River indicate aslight decrease in sulphate levels, and ashas been noted earlier, pH values haveexhibited a slight increase over the samegeneral period. This apparent decreasein sulphate concentration may be anartifact of changes in analytic


20

1 3 5 7 9 11 13Month

0

50

100

150

200

250

Alka

linity

(mg/

l)

Figure 12 Seasonal trend in freshwateralkalinity.

1 3 5 7 9 11 13Month

0

10

20

30

40

50

60

70

80

Cal

cium

(mg/

l)

Figure 13 Seasonal trend in freshwatercalcium concentrations.

methodology. It may also be related, atleast in part, to an overall improvement inthe quality of precipitation falling on theregion. There has been a 28-40%reduction in precipitation of sulphate inthe Atlantic Provinces since 1980(Environment Canada, 1998).

In addition to long term trends, calciumand alkalinity concentrations in surfacewaters follow seasonal patterns withmaximum concentrations of alkalinity(Figure 12), and calcium (Figure 13)generally occurring during mid summer toearly fall, and minimums occurring duringthe spring. This pattern correlates wellwith the expected relative distribution ofsurface run-off and baseflow during thewater year, with the highest values forthese two dominant inorganic species,coinciding with the period wheregroundwater discharge, represented asbaseflow, comprises the highestproportion of total stream flow.

Estuarine waters

Estuarine waters represent a mixture offresh and marine waters, and their major

ion characteristics reflect the relativeproportions of “sodium - chloride type”marine waters, and the fresh watersdescribed above. It is more difficult tomake broad generalizations about themajor ion content of these waters, even atindividual sampling stations, because ofthe dynamic nature of this mixingprocess. As a consequence, meanvalues should be interpreted with caution.They should not be taken to reflectaverage concentrations for P.E.I.estuaries, but rather are a reflection of theaverage position of sampling stationswithin the estuarine environment.

Because of the very high concentration ofdissolved solids in marine waters relativeto freshwater, water in all but the furthestupstream reaches of the Island’sestuaries would be characterized as asodium chloride type. Table 4 presentsmean values and ranges for major ionsanalysed in estuarine waters on P.E.I.

Sodium and chloride comprise over 85%of the dissolved inorganic constituents inseawater, while their concentrations infresh water are virtually negligible incomparison. As a result the observed


21

Table 4 Major Ion Chemistry of Estuarine Waters

Parameter Mean Range

calcium mg/l 247 10.5 - 1050

magnesium mg/l 894 LD - 1600

sodium mg/l 5777 2.5 - 9500

potassium mg/l 304 0.7 - 750

alkalinity* mg/l 99.8 24.9 - 165

chloride mg/l 10768 6.4 - 18500

sulphate mg/l 1658 LD - 2995

salinity ‰ 21.6 0.7 - 28.1

* alkalinity used here as a proxy for bicarbonate

range of sodium and chlorideconcentrations from the estuarinesamples can provide a crude estimate ofthe relative proportions of fresh andmarine waters represented at these sites.The results of such a calculation indicatethat samples collected range fromvirtually fresh water to waters comprisedof 88% to 95% seawater. Mean sodiumand chloride values suggest that onaverage the samples representapproximately 60% seawater and 40%freshwater.

The major ion chemistry of waters frommost estuarine stations have not beenexamined on a regular basis since themid 1970's Because of the constancy ofthe composition of seawater, and thedominant influence it has on the major ioncharacteristics of estuarine waters, it isnot expected that temporal trends wouldbe observed for these elements in thedata set representing estuarine sites.

3.3 Nutrients / Chlorophyll

Nutrients are assessed apart from othermajor ions in this report because of theirparticular significance in both P.E.I.groundwaters and surface waters, andbecause unlike the major ions discussedin section 3.2, anthropogenic influencesare believed to be the controlling factorsin the abundance and distribution of theseparameters on P.E.I. Both nitrogen andphosphorous are essential plant nutrients,however over-enrichment of surfacewaters can have a significant influence onthe trophic status of surface watersystems. Nitrogen, in the form of nitrite,is also of concern in relation to drinkingwater supplies. However, it is normallyassessed as part of a nitrate analysis andcompared to a nitrate guidelineformulated with this in mind. Chlorophyllis also discussed in this section as itsconcentration in phytoplankton isintimately related to nutrient loading andexcesses are ultimately the end result ofnutrient enrichment.


22

3.3.1 Nitrogen

Although various nitrogen species areubiquitous in the environment,background or “natural” levels of nitrogenin groundwater and surface water arerelatively low, and not generally ofconcern. Anthropogenic sources ofnitrogen, particularly fertilizers, animaland human wastes and some industrialeffluents exert a significant influence onnitrogen levels in the aquaticenvironment, resulting in observedconcentrations several times greater thanpresumed “background levels”. While themovement and fate of nitrogencompounds through the environmentinvolves a single, albeit complex system,its distribution is discussed here under theheadings of groundwater, fresh surfacewater and estuarine waters because ofdifferent impacts in each of theserespective environments. Theinterconnection between theseenvironments is important however,particularly the substantial influencegroundwater quality is expected to haveon surface water quality.

Groundwater

Nitrate, expressed here as mg/l nitrate-nitrogen (NO3-N) is the most stable, andthus dominant form of nitrogen found intypical, well oxygenated groundwaters onP.E.I. In some rare instances, particularlyunder highly reducing conditions,ammonia may be detected at levels ofsignificance. For the majority of caseshowever, nitrate is considered to behaveconservatively in groundwater flowsystems on P.E.I., and is the onlynitrogen species discussed with respectto groundwater quality.

The mean nitrate nitrogen concentrationsfor all groundwater stations is 2 mg/l, with3% of the sites having at least one valueexceeding the 10 mg/l guidelinerecommended in the Guidelines forCanadian Drinking Water Quality. Thisguideline has been developed inresponse to an association between highnitrate concentrations in drinking watera n d t h e o c c u r r e n c e o fmethemoglobinemia in young infants.None of the current network sites hadvalues exceeding 10 mg/l. Meanconcentrations from individual wells rangefrom less than the detection limit to 6.8mg/l. Generally speaking, seasonaltrends for nitrate in P.E.I. groundwater arenot readily apparent, except in relativelyshallow wells (Somers, 1998). Ammoniawas detected in 33 of 86 groundwatersamples but at levels below any publichealth significance. The mean ammoniaconcentration of groundwater sampleswas 0.005 mg/l.

Since long-term groundwater qualitystations were only established in the early1990's, the relatively short period ofrecord for these sites does not permit theidentification of any trends in groundwaternitrate concentrations. However,evidence from other research does causesome concern both in terms of the currentdistribution of nitrates in groundwater, andimplications for the future.

Previous work by the P.E.I. Department ofFisheries and Environment (Somers,1998) indicates a strong relationshipbetween land use and groundwaternitrate concentrations, with heavilyimpacted groundwater, frequentlyexhibiting nitrate concentrations 3 to 4times “background levels”. Other workhas shown that 1-2% of all wells tested on


23

the Island exceed recommended levels(Bukowski, J., Somers, G., and Bryanton,J., 1997) and in some watersheds, waterfrom as many as 6 to 7 % of wells doesnot meet the 10 mg/l drinking waterguideline (Swain, 1995). In addition,there is some evidence to suggest thatgroundwater nitrate concentrations areincreasing in at least some areas of theIsland. Although much of the evidencefrom individual wells is somewhatequivocal, trends from data from othersources appear to correlate with changesin land use (Somers 1998).

Aggregate data from records of the P.E.I.Dept. of Technology and Environment, forthe Province as a whole (Somers 1999)shows a slight increase in average nitrateconcentrations in private wells from about3.15 to 3.5 mg/l over the past 10 years.On a more regional basis, moresignificant increases are seen in westernPrince and northeastern Kings Counties,with virtually no change in eastern PrinceCounty. This pattern could be interpretedto indicate that groundwater quality is stillresponding to changes in land use(moving toward more intensive cultivation)in the north eastern and western portionsof the Island, while conditions may havereached some form of steady state orequilibrium between nitrogen inputs andoutputs in eastern Prince County, whereland use may not have changed muchover the past few decades. This “theory”must be viewed with caution however,and needs to be confirmed with morethorough research.

Paradoxically, water quality data fromindividual wells over approximately thesame time, shows no clear trend, withnearly as many wells showing decreasesin nitrate concentrations as those showing

increases. Furthermore, there is no cleargeographic pattern to the data. Thisphenomena underlines the fact that thereis a considerable range of nitrateconcentrations observed in any one area,and highlights the uniqueness of resultsfrom each individual well.

As will be discussed in more detail below,results from surface water samples lendsome support to the suggestion thatgroundwater nitrate concentrations areincreasing in some portions of theProvince. Given the well established linkbetween land use and nitrateconcentrations in groundwater, recentexpansion of potato acreage in theProvince could be expected to result in aneven greater frequency of elevated nitratelevels in domestic water supplies, and aswill be discussed, has considerablesignificance for surface water quality.

Supporting evidence for a trend ofincreasing nitrate concentrations can befound in surface water data. Becausesuch a high proportion of the water inIsland fresh water streams is baseflowfrom groundwater, surface water samplescollected under dry summer conditionscan be expected to be fair approximationsof “average” groundwater quality in thewatershed. Dry weather surface waterdata from the Dunk, Mill and Morell Riversall show increasing nitrate concentrationsthat more or less correspond to theobserved “aggregate” groundwater datanoted above, including a “levelling off” ofnitrate concentrations in the Dunk River,more or less corresponding with theobserved lack of change in averagegroundwater nitrate concentrations in theeast Prince area over the past 10 years.Crude mass balance calculations(Somers 1998), assuming approximate


24

distributions of land use and associatednitrate leaching losses, also compare wellwith observed concentrations inintensively cultivated areas and moreundeveloped watersheds respectively,lending some support to the notion thatobserved concentrations in areas such asthe Dunk River may in fact represent“steady state” conditions.

At this point, temporal aspects of therelationship between land use and the linkto water quality are not sufficiently welldefined to determine if the full extent ofthe current land management practiceson water quality have been witnessed.Among the many confounding factors, arethe variable nature of many agriculturalpractices on nitrate losses, and thevariability in transit time for groundwaterthrough different reaches of thegroundwater flow system. Furtherresearch is needed to address theseissues in a quantitative manner.

Fresh Surface Waters

The introduction to section 3.3 raisedconcerns about the level of nutrients inthe Province’s surface water systems.The nitrogen content of fresh surfacewaters is not so much a concern to thefresh water aquatic habitat itself, but tothe important role these waters play in thetransport of nutrients to estuarineenvironments, where their contribution toeutrophication can be significant. Nitrogen has been measured at freshsurface water stations as ammonia,nitrate and total nitrogen. As withgroundwaters, ammonia is not normallypresent in significant quantities, and mostinorganic nitrogen is found as nitrate-nitrogen. Mean ammonia, nitrate and

total nitrogen levels from fresh waterstations are 0.02, 1.7 and 2.1 mg/lrespectively.

The CCME guideline for total ammonia,for the protection of aquatic life rangesfrom 1.37 to 2.2 mg/l, depending on pHand temperature. The meanconcentration of 0.02 mg/l observed atfresh surface water stations issignificantly below this level, and nosamples exceeded the recommendedlevel. Data from long term stations revealdeclining ammonia concentrations in theProvince’s fresh waters. No readyexplanation for this trend has beenidentified, although different analyticmethods were used over the period ofrecord represented by the data set.

The concentrations of nitrate found innatural waters is well below the levelsconsidered to be toxic for fresh waterorganisms, and no Canadian guidelinelevel for the protection of aquatic life hasbeen adopted. However as noted above,nitrogen is of concern because of it’s rolein the stimulation of excessive primaryproductivity, and both Alberta (1977) andSaskatchewan (1983) have adopted“multi-purpose” water quality objectivesfor total nitrogen at a level of 1 mg/l.Nitrate and total nitrogen levels observedat fresh water stations on P.E.I. regularlyexceed these levels, and even the meanconcentrations noted above areconsiderably in excess of this value.

Overall nitrate concentrations show amuted seasonal trend in the Island's freshwaters (Figure 14), with concentrationsrising through the summer months andreaching a peak in August beforegradually decreasing during the fall andwinter. Seasonal total nitrogen


25

1 3 5 7 9 11 13Month

0

1

2

3

4

5

6

7

8

9

10

Nitr

ate

(mg/

l)

Figure 14 Seasonal freshwater nitratetrends.

1 3 5 7 9 11 13Month

0

1

2

3

4

5

6

7

8

Tota

l Nitr

ogen

(mg/

l)

Figure 15 Seasonal trends in freshwatertotal nitrogen concentration.

1975 1980 1985 1990 1995 2000Year

0

1

2

3

4

Tota

l Nitr

ogen

(mg/

l)

Figure 16 Long term trends in totalnitrogen in the Mill, Dunk and Morell Rivers.Mill River (PE01CA0001) - solid line;Dunk River (PE01CB0001) - long dashes;Morell River (PE01CD0003) - short dashes.

1960 1970 1980 1990 2000Year

0

1

2

3

4

Nitr

ate

(mg/

l)

Figure 17 Long term trends in nitrate inthe Mill, Dunk and Morell Rivers.Mill River (PE01CA0001) - solid line;Dunk River (PE01CB0001) - long dashes;Morell River (PE01CD0003) - short dashes.

concentrations show similar trends to thatof nitrate (Figure 15).

As inferred in the preceding discussion ofgroundwater, data from long termmonitoring stations indicate that nitrateand total nitrogen concentrations havebeen progressively increasing over theperiod of record. Mean total nitrogenlevels in samples from stations on theDunk River have changed fromapproximately 2 mg/l increasing to 3 mg/lover the past 18 years (Figure 16).

Nitrate levels have doubled in the Mill,Dunk and Morell River over the past 20-30 years (Figure 17).

At other sampling sites, mean totalnitrogen concentrations exceeding 4 and5 mg/l have been observed in somewatersheds. The Wilmot River andWright’s Creek have mean nitrate levelsof 4.0 mg/l and 6.5 mg/l respectively.Wright’s Creek had a maximum nitratelevel of 9.0 mg/l. The high nitrateconcentrations in Wright’s Creek may be


26

related to runoff from urban andagricultural lands as well as input fromrunoff of deicing fluid from CharlottetownAirport. In contrast, the mean totalnitrogen concentration in the Bear River,a relatively “pristine” or “undeveloped”watershed, is 0.37 mg/l and the maximumobserved concentration to date has been0.71 mg/l.

Estuarine Waters

Nitrogen levels are of prime concern inP.E.I. estuaries, and concentrations aslow as 2-4 mg/l in fresh water sourceshave resulted in estuarine eutrophication,symptoms of anoxia, obnoxious smells,and excessive algal growth. TotalKjeldahl nitrogen plus nitrate levels(TKN+NO3) observed at estuarinesampling stations during the mid 1970'saveraged 0.12 mg/l.

Mean nitrate concentrations for samplingstations in mid-estuarine environments ofthe current index basins are: Mill River0.27 mg/l(PE01CA0015), West River 0.61mg/l (PE01CC0113) and Montague River0.25 mg/l (PE01CE0103).

Because of the dynamic nature of themixing of fresh and marine waters foundin estuaries, differences in nitrogenconcentration should be expected indifferent parts of these water bodies.Furthermore, because a number of otherfactors play an important role indetermining the impact of nitrogen inthese waters, direct comparison of thesignificance of nitrogen levels fromestuary to estuary, or between differentportions of a single estuary may not bemeaningful. As a consequence, anassessment of the significance of any

spatial differences in total nitrogenconcentrations in estuarine waters is notpossible.

As recent data has not been analysed fortotal nitrogen for the network, long termtemporal comparisons are not possible.Nitrate, while it has been measured inboth historical and recent estuarinesamples, has not been measured at thesame long term stations to provide a long-term record at the same location (as hasbeen the case for several fresh waterstations). In addition, the relationship ofnitrogen to chlorophyll concentrations isalso not possible as the chlorophyllanalyses date from the 1990's while theTKN+NO3 analyses are from the late1970's.

3.3.2 Phosphorus

Phosphorus is a nutrient that has comeunder considerable scrutiny during thelast number of decades for its role incausing undesirable eutrophication oflake environments. The paucity of lakeson P.E.I. minimizes its importance onP.E.I.’s freshwater environments but itcertainly has considerable influence onwater quality in the hundreds ofman-made impoundments present onP.E.I. Recently, contrary to conventionalwisdom, phosphorus has beendetermined to be an important limitingnutrient in a P.E.I. estuary (Meeuwig,1998). While common sources ofphosphorus in the past included laundrydetergents and other household cleaners,in agricultural areas such as P.E.I., thedominant source is likely the extensiveusage of inorganic phosphorus fertilizers.


27

1970 1980 1990 2000Year

0.010

0.100

1.000

Tot a

l Pho

spho

rus

(mg/

l )

Figure 18 Long term trends in totalphosphorus in the Mill, Dunk and MorellRivers.Mill River (PE01CA0001) - solid lineDunk River (PE01CB0001) - long dashesMorell River (PE01CD0003) - short dashes

Groundwater

Phosphorous concentrat ions ingroundwater may reflect natural sources,or anthropogenic influences, particularlyon-site sewage disposal and thepresence of phosphates in manydetergents. Conventional wisdom hasnormally held that phosphorous isretained by soils, and leaching ofsignificant levels of phosphorous to thewater table is not normally anticipatedunder usual conditions. The meanconcentration of total phosphorous ingroundwater samples is 0.055 mg/l. Atthe concentrations normally found ingroundwater, phosphorous is not aconcern, and there is no drinking waterguideline for phosphorous in Canada.The EEC has recommended a maximumadmissible concentration of 5 mg/l fortotal phosphorus for drinking waters.


The mean total phosphorous levels forfresh surface waters for the province is0.049 mg/l and the mean concentrationof phosphate is reported as 0.027 mg/l.

For the three stations with long termrecords, there are several notable trends(Figure 18). Firstly, the generalrelationship of total phosphorusconcentrations between the stations isdifferent than that observed for nitrogen.For nitrogen, the Morell River(PE01CD0003) has the lowestconcentrations (Figures 16 and 17).However, for total phosphorus, theconcentrations in the Morell River areapproximately equal to that of the DunkRiver (PE01CB0001).

Another notable trend in the long termphosphorus record is that for the MillRiver location (PE01CA0001), there wasa long term decrease until approximately1989 when concentrations began toincrease. Increasing concentrations alsoappear to have occurred in the DunkRiver since 1989.

There are no Canadian fresh wateraquatic guidelines for this nutrient butAlberta has a limit of 0.15 mg/l forphosphorus. Thirty-two samples of 1366(2%) exceed the Alberta guideline level.

A comparison of the long term stations tothe Bear River station in a relativelyundeveloped watershed is not asdramatic for total phosphorus as it is fornitrogen (see Section 3.3.1). Meanphosphorous concentrations for the Mill,Dunk and Morell Rivers are 0.03 mg/l,0.06 mg/l, and 0.04 mg/l respectively withmaximums of 3.3 mg/l, 0.96 mg/l, and0.33 mg/l while mean concentrations inthe Bear River are 0.028 mg/l with a


28

1970 1980 1990 2000Year

0.0

0.05

0.10

0.15

0.20

0.25

Tota

l Pho

spho

rus

(mg/

l)

Figure 19 Long term trends in totalphosphorus in the Mill, West and MontagueRiver estuaries.

maximum of 0.039 mg/l.

As noted earlier, phosphorous is normallyconsidered to be well bound to soilparticles and the movement ofphosphorous in the environment might beexpected to show some relationship tomovement of sediment. The average andmaximum turbidity values for the fourstations mentioned above are differentfrom each other but do not mirror the totalphosphorus concentrations for thesestations.

Phosphorous levels in the full data setwere compared with turbidity andsuspended sediment concentrations.Regression analysis revealed that there isa weak relationship (R2 value of 0.320)be tween suspended sed imentconcent ra t ions ( tu rb id i t y) andphosphorous levels in the fresh waterrivers and streams. While therelationship is relatively weak, it is alsonoted that currently available turbiditymeasurements, based on grab samplesmay not be a good reflection of overallsediment movement (see discussion insection 3.1). The relationship betweenturbidity, suspended sediment andphosphorous levels in surface waters isthe focus of on-going monitoring.

Seasonally, phosphorous concentrationsdon’t display appreciable variability. It isnot clear whether this is due to theinfluence of groundwater on surface waterconcentrat ions, the in f requentappearance of highly turbid samples orsome other unknown influence.

Estuarine Waters

The mean total phosphorus levels for

estuarine waters is 0.04 mg/l. Using atechnique referred to as the "RedfieldRatio" which compares total nitrogen andtotal phosphorus levels (Redfield, A.C.,1934), it is possible to assess the relativeroles of these nutrients as limiting factorsin aquatic productivity in estuarineenvironments. The Redfield Ratiocalculated for the estuarine data prior to1980 is 21:1. This suggests that PEI’sestuaries are phosphorus limited whichcorresponds with a recent assessment ofthe Mill River Estuary (Meeuwig, 1998).There is insufficient data to determine theratio in later years. The observation inthe Mill River study that the ratio isdropping over time cannot be fullyassessed with this data set.

There are no sampling stations that weresampled in both the current network andduring the 1970's. However, there werea number of stations that were sampled inthe 1970's that were near to some of thepresent locations in the network. At thesesites, there appears to have generallybeen an increase in the total phosphorusconcentrations between the two timeframes (Figure 19). The most marked isnear the mouth of the West River where


29

1 3 5 7 9 11 13Month

0.1

1.0

10.0

Chl

orop

hyll

(µg/

l)

Figure 20 Seasonal trends in freshwaterchlorophyll concentrations.

1 3 5 7 9 11 13Month

0.1

1.0

10.0

Chl

orop

hyll

(µg/

l)

Figure 21 Seasonal trends in estuarinechlorophyll concentrations.

concentrations have increased from~0.02 to ~0.05 mg/l.

3.3.3 Chlorophyll

The measurement of chlorophyll has,over the last number of decades, becomean essential tool in the assessment oftrophic status of surface waters. P.E.I. isno exception especially in estuarinewater. As chlorophyll has no utility whenassessing ground water, it is not analysedin groundwater samples and thus will notbe discussed here.


The mean chlorophyll concentration forfresh surface waters for the province is1.6 �g/l. Seasonally, chlorophyllconcentrations show a strong trend withthe peak normally occurring in July orAugust with an average of ~2 �g/l (Figure20). Minimum concentrations tend tooccur in February at approximately 0.3�g/l. The maximum concentrationobserved was 43.4 at stationPE01CC0004 in the lower part of theWinter River. This concentration was

highly unusual for this location and wouldnot be suggestive of eutrophic conditions.Nevertheless, on P.E.I., with phosphorusconcentrations normally being adequateto support higher trophic levels, it is notuncommon for ponds to exhibit highproductivity.

There are no Canadian guidelines for theconcentration of chlorophyll, however,such a guideline would normally beapplicable to lake systems and might notnecessarily be applicable to streams onP.E.I.

Estuarine Waters

Average concentrations of chlorophyll inthe network estuarine data is 4.3 �g/l.Chlorophyll has only been measured inthe network since 1991 at three stationsin each of the Mill, West and MontagueRivers. Seasonally there are strongtrends with high concentrations ofapproximately 5 �g/l during June throughSeptember (Figure 21). An annual peakwould be expected to occur during aspring bloom however, sampling is notnormally possible at this time of yearbecause of ice conditions during the


30

spring break-up.

Of the three estuaries in the network,both the Mill and West Rivers exhibit fallconcentrations lower than the summerconcentrations. The Montague River, onthe other hand, exhibits fall chlorophylllevels that are higher than those in thesummer. While there is no readyexplanation for this difference, it doessuggest that the fall phytoplankton bloomis a strong phenomenon in the MontagueRiver. The highest concentrationobserved was 24.5 �g/l at stationPE01CE0096 in the Montague River.Low concentrations occur during thewinter at approximately 1 �g/l.

Overall, concentrations that wereobserved in the estuaries suggest thateach of the estuaries is at a mesotrophiclevel of primary productivity. This is animportant observation as the Mill Riverhas been assessed in a morecomprehensive data set as beingeutrophic in its upper reaches. Thenetwork station on the Mill River that islocated in the area of eutrophic conditionshas concentrations that are similar to thatfound in the other study. Indeed, thehighest chlorophyll levels at that stationtend to have occurred in the last fewyears of the data set. This is consistentwith local observations that the primaryproductivity and anoxic conditions havebeen at their worst ever in the last fewyears in the upper part of the Mill Riverestuary. The observation of mesotrophicstatus in the West River is also importantas that estuary suffered from eutrophicconditions in the mid-eighties prior to amodification to a causeway in the centreof the river restored natural tidal flushingto the estuary.

Long term trends for chlorophyll are notreadily apparent and this may be due tothe relatively short time frame of theobservations. Nevertheless, theincreasing frequency and number oflocations that anoxic conditions areobserved on P.E.I. suggest that overall,chlorophyll concentrations may beincreasing although individual estuarieswould of course be exhibiting chlorophyllconcentrations reflecting each individualset of watershed inputs.

3.4 Metals

3.4.1 Analytical Results

Analysis of samples collected from thewater quality network from groundwater,fresh surface water and estuarineenvironments includes a suite of 15metals. Most of these parameters arenaturally occurring in the environment atleast at low levels, while others are not ascommonly found in the environmentexcept through anthropogenic influences.

Tables 5 and 6 summarize the results ofmetal analyses for groundwater and freshsurface water sampling stationsrespectively. Short descriptive sectionson selected, individual parameters areincluded later in this section to highlightsome of the more important results of theanalyses, or to suggest possible sources,or implications of these metals in theirrespective environments.

Groundwater

The majority of metals analysed ingroundwater samples were detected on afrequent basis, although concentrations


31

Table 5 Metal Concentrations in Groundwater (mg/l)

Parameter(total except

whereindicated)

Mean “station”

concentration

Standarddeviation

Maximumconcentration(all samples)

Drinkingwater

guideline

% of stationsexceedingguideline

aluminum 0.005 0.004 0.057

arsenic 0.001 0.002 0.026 0.025 2 (1/50)

barium 0.37 0.27 1.13 1 5 (1/19)

beryllium 0.002 0.005 0.06

cadmium 0.00001 0.00001 0.0014 0.005 0

chromium 0.0006 0.0005 0.013 0.05 0

cobalt 0.0001 0.0001 0.0004

copper 0.005 0.004 0.060 1* 0

iron 0.012 0.008 0.427 0.3* 6 (1/18)

lead 0.0004 0.0007 0.054 0.01 10 (2/20)

lithium 0.003 0.003 0.016

manganese 0.0005 0.0005 0.038 0.05* 0

mercury(extractable)

0.000002 0.000011 0.00007 0.001

molybdenum 0.00002 0.00003 0.0017

nickel 0.00003 0.00007 0.007

selenium 0.0001 0.0001 0.0022 0.1 0

strontium 0.14 0.17 0.799

vanadium 0.005 0.004 0.015

zinc 0.024 0.024 0.415 5* 0

* guideline based on aesthetic considerations

were low relative to guidelines fordrinking water quality, and for the mostpart, are presumed to reflect backgroundconcentrations as a result of naturalprocesses or ambient concentrations inrecharging waters. With few exceptions,there appears to be little variation

between the metals content ofgroundwaters across the Island. Thisrelatively uniform distribution could betaken to suggest that the geological ratherthan anthropogenic factors play thedominant role in metals composition ofP.E.I. groundwaters.


32

Table 6 Metal Concentrations in Fresh Surface Water (mg/l)

Parameter(total except

whereindicated)

Mean“station”

concentration

Standarddeviation

Maximumconcentration(all samples)

Fresh wateraquatic lifeguideline

% ofstations

exceedingguideline

aluminum 0.150 0.20701 4.68 0.1 81 (22/27)

arsenic 0.0014 0.00295 0.016 0.05 0

barium 0.10387 0.05702 0.446 5* 0

beryllium 0.00316 0.00985 0.05 n/a n/a

cadmium 0.00002 0.00002 0.0004 0.0008 0

chromium 0.00036 0.00020 0.0074 0.02-0.002**

22 (6/27)

cobalt 0.00014 0.00007 0.0017 n/a n/a

copper 0.00071 0.00044 0.0134 0.002 59 (16/27)

iron 0.25710 0.25493 5.74 0.3 67 (18/27)

lead 0.00014 0.00018 0.0056 0.002 15 (4/27)

lithium 0.00112 0.00052 0.00750 n/a n/a

manganese 0.02826 0.01764 0.238 0.1-1.0* 22 (6/27)

mercury(extractable)

0.0000595 0.0006656 0.0034 0.0001 64 (14/22)

molybdenum 0.00003 0.00007 0.00036 n/a n/a

nickel 0.00011 0.00014 0.0032 0.065 0

selenium 0.00008 0.00005 0.00016 0.001 0

strontium 0.04270 0.02612 0.08927 n/a n/a

vanadium 0.00291 0.00241 0.01021 n/a n/a

zinc 0.00194 0.00283 0.313 0.03 7 (2/27)

* B.C. Guideline

** 0.02 for fish, 0.002 for zooplankton and phytoplankton

Three parameters, arsenic, barium andlead were detected at concentrationsabove their respective health baseddrinking water guideline, although in each

case more than 99% of samples were incompliance with recommended levels.

Results of surface water sampling show


33

more variability, possibly as a result of thegreater number of potential influences onsurface water quality and also because ofthe much longer period of record.Whereas groundwaters may be expectedto be influenced by the quality ofprecipitation, local aquifer materials andonly very local anthropogenic influences,in addition to these factors surface watersare also influenced by a host ofconstituents that may be present in directrunoff.

A number of metals (including aluminum,cadmium, copper, iron, lead, manganeseand mercury) have been detected atlevels exceeding values recommendedfor the protection of aquatic life on arelatively frequent basis. In at least someof these cases however, analyses are fortotal or extractable metal concentrations,and may reflect the presence of thesemetals in association with sediment ratherthan dissolved species in the watercolumn. In these cases, it is questionablewhat implications these values have forthe health of aquatic ecosystems. Primeexamples of this are aluminum, iron andmanganese. The occurrence andimplications of these metals areaddressed further under the respectivesections on individual parameters.

Very few analyses for metals in estuarinewaters have been conducted and theavailable data are insufficient to draw anymeaningful conclusions for metals in thisenvironment. Furthermore, guidelinesagainst which to evaluate the significanceof metals concentrations in thisenvironment are not readily available. Asa consequence, no discussion of metalsfrom estuarine sampling stations areincluded in this report.

3.4.2 Comments on theoccurrence of selectedmetals

Aluminum

Aluminum is one of the most abundantelements on earth, but because of itslimited solubility, concentrations ofdissolved species in natural waters aregenerally not high. In the absence ofanthropogenic sources, most aluminum isderived from the natural weathering ofrock materials, and may be present inclays, complexes or free (dissolved)aluminum.

In drinking water, elevated levels ofdissolved aluminum are often associatedwith water treatment processes, and therehas been considerable discussion aboutpossible association between aluminumin drinking water and Alzheimer’sdisease, but no causal association hasbeen established. While no drinkingwater guideline has been established inCanada at this point, the EEC hasestablished a guideline of 0.05 mg/l forthis metal. However drinking water onP.E.I. is derived from groundwatersources and is not treated withcoagulants, and the mean concentrationfor total aluminum was only 0.005 mg/l.

Aluminum concentrations can also be ofconcern for freshwater aquatic habitatand may pose health risks to a number offish species, with possible impacts on theearly developmental stages of salmonids,the sac fry of lake trout, as well as thecleavage embryos of rainbow trout (Gunnand Keller, 1984). The CCME guidelinefor total aluminum ranges from 0.005 to0.1 mg/l depending upon pH, Ca ionconcentrations, and DOC content.


34

Data from fresh surface water stationsshow aluminum levels frequentlyexceeding even the higher end of thisrange with mean concentrations of 0.150mg/l. Indeed, 26% of the fresh watersamples exceed 0.1 mg/l.

It is notable that a reasonably closecorrelation exists between aluminumlevels and turbidity, suggesting that muchof the observed aluminum may beassociated with sediment in some boundform. If this is the case, and dissolvedaluminum levels are in fact low, the bio-availability of aluminum, and itssignificance to aquatic habitat in thisenvironment, may be of limitedimportance.

Mean concentrations for the Dunk, Milland Morell Rivers, are 0.133 mg/l, 0.158mg/l, and 0.051 mg/l respectively.Sample site PE01CC0042 (Winter River)has high total aluminum concentrationswith a mean of 0.25 mg/l. In contrast,aluminum levels in the Bear River, arelatively undeveloped area of theProvince are much lower, with an averagetotal aluminum concentration of 0.054mg/l. It is interesting to note that turbiditylevels in the Bear River are also an orderof magnitude lower than the Dunk River.This association would tend to lendsupport to the suggestion that much ofthe observed distribution of aluminumrelates to suspended sediment in thewater column.

Arsenic

Arsenic is widely distributed in geologicalmaterials, however generally, significantcontributions of arsenic to natural watersare normal ly associated with

environments where signif icantweathering or leaching of arsenic bearingsulphide minerals is occurring. Arsenichas also been widely used in a number ofcommercial and industrial applications,including in some pesticide products. Thegeologic environment in P.E.I. is notconsistent with significant natural sourcesof arsenic, and anthropogenic influencesmay determine any occurrence ofelevated levels of arsenic in Islandgroundwater and surface waters. Meanarsenic levels in Island groundwater andsurface waters are 0.001 and 0.0014 mg/lrespectively, well below levels of concern.2% of groundwater samples (from as ingle s ta t ion) exceeded therecommended drinking water guideline of0.025 mg/l with a maximum concentrationof 0.026 mg/l. Given the relativeuniformity of other groundwater results(standard deviation from mean of 0.002)the minor exceedance of the guideline isconsidered as a spurious result.

Barium

Barium is a naturally occurringcomponent of many minerals, normallyoccurring in trace levels in feldspars andclays and levels are often higher ingroundwaters than surface waters. Theaverage barium concentration observedin groundwaters was 0.37 mg/l and all ofthe 280 groundwater samples tested forbarium had detectable concentrations ofthis metal. Higher barium concentrationswere found at two locations in WesternP.E.I. At Bloomfield Elementary School(PE01CA0045) the mean concentrationwas 0.87 mg/l and Hernwood Junior HighSchool (PE01CA0046) a meanconcentration of 0.43 mg/l was observed.Only one sample, collected at Bloomfield


35

Elementary School at 1.13 mg/l,exceeded the drinking water guideline of1.0 mg/l. Based on the limited number ofgroundwater stations, it is difficult todetermine whether these are anomalousconcentrations or not, however it isprobable that they reflect local geologicalconditions.

There are no Canadian guidelines for theprotection of aquatic life for bariumalthough the Province of British Columbiahas established an MAC for theprotection of fresh water aquatic life at 5.0mg/l barium. The mean concentration ofthis metal in fresh surface watersobserved on P.E.I. is 0.10 mg/l, with amaximum of 0.44 mg/l.

Cadmium

Although cadmium occurs naturally insome minerals, major sources ofcadmium in the environment are fromanthropogenic activities including mining,manufacturing and agricultural use ofsludges, fertilizers and pesticidescontaining cadmium, and the burning offossil fuels (CCME, 1987). Cadmium wasdetected in 4% of 308 groundwatersamples, with a maximum concentrationof 0.0014 mg/l. The maximumacceptable concentration (MAC)recommended in the Guidelines forCanadian Drinking Water Quality is 0.005mg/l.

For the protection of aquatic life, theCCME re c ommends cadmiumconcentrations should be below therange of 0.0002-0.0018 mg/l dependingon water hardness. For typical P.E.I.surface waters, the appropriate value is0.0008 mg/l. Mean cadmium

concentrations for fresh surface waters is0.00002 mg/l, with a maximum value of0.0004 mg/l

Chromium

Although chromium may enter the aquaticenvironment from the weathering ofchromium bearing minerals or fromanthropogenic sources, given the geologyof the Island it is likely that anthropogenicactivities would be the dominant influenceon its distribution in waters on P.E.I.

Chromium was detected in 86% ofgroundwater samples, although levelswere low with a mean concentration of0.0006 mg/l and a maximumconcentration of 0.013 mg/l. TheGuidelines for Canadian Drinking WaterQuality recommend chromium levels donot exceed 0.05 mg/l.

Chromium was also detected in freshsurface water stations, albeit generally atvery low levels with a mean concentrationof 0.00036 mg/l. The CCME hasestablished a guideline of 0.02 mg/l forthe protection of fish and 0.002 mg/l forthe protection of aquatic life (i.e.zooplankton and phytoplankton) (CCME,1987). 1.4% of stream water samplesexceed the 0.002 mg/l guideline foraquatic life with a maximum concentrationof 0.0074 mg/l recorded for the DunkRiver. Chromium concentrations for thefresh surface waters tend to be sitespecific and do not appear to showregional or temporal trends. Values inexcess of the recommended levels wererecorded at 6 of 27 stations( P E 0 1 C A 0 0 0 1 , P E 0 1 C A 0 0 4 4 ,P E 0 1 C B 0 0 0 1 , P E 0 1 C B 0 1 4 1 ,PE01CC0010, and PE01CC021).


36

Chromium has not been measured atestuarine stations in the network.

Copper

Copper may be released to the aquaticenvironment from the weathering of avariety of minerals, or through a variety ofanthropogenic activities. Copper at theconcentrations commonly found indrinking water is not a health concern, butelevated levels may cause staining offixtures, enhanced corrosion of othermetals, and impart an unpleasant taste towater. Based on these aestheticconsiderations, the Guidelines forCanadian Drinking Water Qualityrecommend that copper concentrationsdo not exceed 1 mg/l. The meanconcentration of extractable copperobserved at groundwater stations is 0.005mg/l, and no samples exceeded the 1.0mg/l aesthetic objective for drinking water.

Elevated copper concentrations pose arisk to trout, as well as to several speciesof invertebrates and aquatic plants(CCME, 1987). The guideline for copperin surface waters, is dependant on waterhardness, and for P.E.I. conditions, aconcentration of 0.002 mg/l would beconsidered protective of aquatic life. Themean value for copper in fresh surfacewaters was 0.00071 mg/l. Data fromfresh water stations indicate mean totalcopper concentrations for individual riversranging from 0.0007 mg/l to 0.001 mg/l.Approximately 13% of samples exceededthe recommended level with a maximumconcentration of 0.0134 mg/l beingrecorded.

Iron

Iron is an abundant naturally occurringcomponent of soils and rocks, and itsoccurrence in natural waters inassociation with sediment is notuncommon, however dissolved ironspecies are only sparingly soluble exceptunder oxygen deficient conditions. Iron atelevated levels is undesirable in potablewater supplies because of aestheticconsiderations and is also undesirable inthe aquatic environment. The guidelinevalues for the protection of aquatic life aswell as for drinking water supplies is 0.3mg/l. Iron concentrations in all but onesample from the groundwater stationswere below this level.

The average concentration of total iron inthe streams and ponds of the province is0.012, with a maximum concentration of0.427 mg/l being observed. As withaluminum, it is possible that much of theiron observed in surface waters isassociated with sediment, and may havelimited environmental significance. Ironconcentrations appear to be closelyrelated to turbidity and a regressionanalysis between iron concentrations andturbidity reveals a strong relationship withan R2 value of 0.756 (Figure 22).

Iron concentrations are variable acrossthe island but tend to be slightly higher inareas of intense agricultural productionsuch as the Dunk River and BradshawRivers, again suggesting a relationshipwith higher concentrations of suspendedsediments in these streams. Total ironconcentrations observed in the relativelypristine Bear River are 0.11 mg/l, whileconcentrations for the Dunk River are0.22 mg/l. Long-term data for iron showsno change in the fresh surface waters


37

0 50 100 150 200Turbidity (JTU)

0

1

2

3

4

5

6

Tota

l Iro

n (m

g/l)

Figure 22 Relationship between totaliron and turbidity. The line shown is a linearregression between total iron and turbidity.

over the past 30 years.

Lead

Elevated concentrations of lead are ofconcern in drinking water and in theaquatic environment. While the naturaloccurrence of lead in groundwater is low,elevated lead levels in drinking watersupplies are normally attributed to theleaching of lead from plumbing fixtures.The mean lead concentration observed insamples from the groundwater stationswas 0.0004 mg/l, below the 0.01 mg/lmaximum acceptable concentrations(MAC) in the Guidelines for CanadianDrinking Water Quality. Only 0.7% ofsamples exceeded the guideline, with amaximum concentration of 0.054 mg/l.

High concentrations of lead in the surfacewaters pose risk to benthic bacteria,freshwater plants, invertebrates and fishas lead can be bio-accumulated by theseaquatic organisms (CCME, 1987). Leadguidelines for the protection of aquatic lifedepend on water hardness and for typicalP.E.I. surface waters the appropriate

value would be 0.002 mg/l. The meanconcentration of lead for stream waters is0.00014 with a maximum concentration of0.0056 mg/l being observed. Lead valuesabove the recommended level wereobserved at 15% of surface waterstations, although no spatial or temporaltrends are apparent in the data.

Manganese

Manganese exhibits similar geochemicalcharacteristics as iron, and whileabundant in rocks and soils, dissolvedmanganese is normally found principallyin oxygen deficient waters. Althoughthere is a drinking water guideline formanganese of 0.05 mg/l, based onaesthetic considerations the meangroundwater concentration was 0.0005mg/l and no samples exceededrecommended levels.

The concentration of manganese in thesurface waters of the province issomewhat higher than for groundwater,with a mean value of 0.028 mg/l. Whilethere are no Canadian guidelinesmanganese in the aquatic environment,British Columbia, has set a guideline of0.1-1.0 mg/l total manganese for theprotection of fresh water fish. Meanmanganese concentrations fall belowthese guidelines, but 4.6% of samples,representing 22% of stations, hadobservations that exceeded the 0.1 mg/lguideline, with a maximum concentrationof 0.238 mg/l.

The manganese concentrations observedin P.E.I. surface waters are in line withthose recorded for the Atlantic provinces(CCME, 1987), and have remained fairlystatic over the past 30 years.


38

Mercury

The drinking water guideline for mercuryis 0.001 mg/l, and mean groundwaterlevels were 0.000002 mg/l, with amaximum concentration of 0.00007 mg/lbeing reported. The mean concentrationof extractable mercury in fresh surfacewaters was slightly higher at 0.0000595mg/l, however 7.5% of samples didexceed the 0.0001 mg/l guideline level setfor the protection of aquatic life (CCME,1987). The maximum concentrationobserved was 0.0034 mg/l.

Zinc

Although there is a drinking waterguideline for zinc of 5 mg/l based onaesthetic considerations, observedgroundwater concentrations were all morethan an order of magnitude below thislevel. Guidelines for the protection ofaquatic life are more stringent withmaximum allowable concentrations of0.03 mg/l (CCME, 1987). Mean zinclevels for fresh surface waters are 0.0019.Only 1.7% of samples exceeded aquaticlife guidelines, and the maximumconcentration observed was 0.313 mg/l.

3.5 Pesticides and selectedother organic chemicals

Over the life of the water quality networka variety of organic compounds havebeen examined, and given theprominence of agriculture in the Island'seconomy and the absence of significantindustrial activity, attention has focusedprimarily on pesticides. Most work onother organic compounds has been

limited to groundwater samples, normallyfrom municipal drinking water supplies.

Much of the work conducted on pesticideshas been the result of specifically focusedprojects rather than general surveillancefrom Island wide networks. As aconsequence, it is difficult in many casesto draw broad generalizations about theoccurrence of pesticides in Island waters,and still place these conclusions in thecontext they belong. The varyingsampling program designs can beexpected to have a strong bearing on thesignificance of individual sampling results.Fortunately, the results of the bulk of thiswork has already been publishedpreviously. For these reasons, briefdescriptions of the more significant workson pesticides are described individually.

3.5.1 Review of Envirodat DataBase

A summary of some of the resultscontained in the Envirodat data base isprovided in Table 7. Results fromprograms that focused on highly sitespecific phenomena, or for which noinformation on sample sites wereavailable, have been excluded from thetable. Only very limited commentary isoffered for the data presented in Table 7,and the reader is directed to the briefsummaries of individual studies presentedbelow, or to the original works. Thereader should note however, that in somecases the data described in thedescriptions below is not represented inthe results included in Table 7.

In total, the table represents data from8196 analyses, and reports some 296pesticide detections (3.6% of analyses).


39

Tabl

e 7

Envi

roda

t res

ults

for p

estic

ide

anal

yses

in g

roun

dwat

er, f

resh

sur

face

wat

er a

nd e

stua

rine

wat

ers.

Pest

icid

eD

etec

tion

Lim

it( ��

g/l)

Gro

undw

ater

Fres

hwat

erEs

tuar

ine

Wat

er

Perc

ent D

etec

ted

Max

. C

onc.

( ��

g/l)

Perc

ent D

etec

ted

Max

. C

onc.

( ��

g/l)

Perc

ent D

etec

ted

Max

. C

onc.

( ��

g/l)

Aldi

carb

0.00

18%

(n=4

21)

4.20

00%

(n=2

7)

Aldr

in0.

001

1%(n

=174

)0.

001

0%(n

=42)

0%(n

=138

)

Atra

zine

0.00

0671

%(n

=21)

0.03

363

%(n

=43)

0.03

2

Azin

phos

met

hyl

0.1

1%(n

=184

)0.

001

4%(n

=24)

0.09

1

Car

bary

l0.

001

0%(n

=151

)0%

(n=3

3)

Car

bofu

ran

0.00

10%

(n=1

35)

0%(n

=32)

0%(n

=3)

Car

boph

enot

hion

11%

(n=1

66)

0.01

9

Chl

orda

ne0.

005

0%(n

=174

)0%

(n=4

2)0%

(n=1

34)

Chl

orfe

nvin

phos

0.1

0%(n

=29)

Chl

orot

halo

nil

0.00

14%

(n=1

08)

0.31

1

Cru

fom

ate

0%(n

=184

)

2,4

D0%

(n=3

1)0%

(n=1

27)

P,P

DD

D0.

001

0%(n

=174

)5%

(n=4

2)0.

002

0%(n

=134

)

P,P

DD

E0.

001

0%(n

=174

)8%

(n=3

9)0.

001

0%(n

=133

)

DD

T0.

001

0%(n

=174

)19

%(n

=42)

0.00

32%

(n=1

34)

0.05

2

Dia

zino

n9%

(n=1

76)

0.00

10%

(n=2

4)

Die

ldrin

0.00

50%

(n=1

74)

0%(n

=42)

0%(n

=134

)

Dim

etho

ate

15%

(n=2

0)0.

033

Dis

ulfo

ton

0.1

3%(n

=172

)0.

008

0%(n

=38)

Endo

sulfa

n0.

005

0%(n

=174

)2%

(n=4

8)0.

008

0%(n

=124

)

7 Envirodat Results for PesticideAnalyses


40

Tabl

e 7

Envi

roda

t res

ults

for p

estic

ide

anal

yses

in g

roun

dwat

er, f

resh

sur

face

wat

er a

nd e

stua

rine

wat

ers

Pest

icid

eD

etec

tion

Lim

it( ��

g/l)

Gro

undw

ater

Fres

hwat

erEs

tuar

ine

Wat

er

Perc

ent D

etec

ted

Max

. C

onc.

( ��

g/l)

Perc

ent D

etec

ted

Max

. C

onc.

( ��

g/l)

Perc

ent D

etec

ted

Max

. C

onc.

( ��

g/l)

Ethi

on0%

(n=1

83)

Fenc

hlor

phos

0%(n

=183

)

Feni

troth

ion

0%(n

=183

)

Hep

tach

lor

0.00

13%

(n=1

74)

0.00

214

%(n

=42)

0.00

10%

(n=1

34)

Hex

achl

oro

benz

ene

0.00

20%

(n=1

95)

0%(n

=9)

4%(n

=24)

0.00

05

Imid

an5%

(n=1

74)

0.00

0009

Imid

iclo

prid

0%(n

=12)

Lind

ane

0.00

12%

(n=1

74)

0.01

117

%(n

=42)

0.00

251

%(n

=135

)0.

018

Linu

ron

0%(n

=14)

Mal

athi

on0%

(n=1

84)

0%(n

=29)

Met

alax

yl10

%(n

=84)

13.7

543

%(n

=14)

0.07

5

Met

ham

idop

hos

14%

(n=7

)0.

007

Met

hida

thio

n0%

(n=2

9)

Met

hoxy

chlo

r0.

010%

(n=1

74)

2%(n

=42)

0.01

0%(n

=134

)

Met

ribuz

in0.

001

24%

(n=2

1)0.

010

6%(n

=52)

0.00

5

Mire

x0.

001

0%(n

=173

)41

%(n

=29)

0.00

6

Para

thio

n1%

(n=1

84)

0.00

7

Phor

ate

1%(n

=183

)0.

001

0%(n

=43)

Sim

azin

e0.

001

52%

(n=2

1)0.

154

0%(n

=14)


41

Just under 5300 of the analyses (32parameters), are from groundwatersamples, with about 2.5% of analysesreporting detectable concentrations.Surface water sampling includes 1157analyses (34 parameters) with about7.7% of analyses reporting detectableconcentrations. Estuarine water sampleswere only analysed for 15 compoundsand account for the remaining 1747analyses. Slightly over 4% of estuarinesamples analysed had detectableconcentrations of pesticides.

In general, all detections were at lowlevels, and only two products wereobserved to exceed published Canadianwater quality guidelines. These twocases, both for surface water sampleswere for DDT, and Endrin, and of the two,only DDT was detected with anyfrequency (19% of 42 samples collected).

The most commonly detected pesticidesoverall were the triazines; atrazine,metribuzin and simazine. Atrazine wasdetected in 42 of 64 analyses, more orless evenly distributed betweengroundwater and fresh surface watersamples. For metribuzin 8 of 73 analysesreported detections, mostly fromgroundwater samples and for simazine,11 of 35 analyses, all from groundwatersamples reported detections. What isperhaps most notable about these figuresis the relatively high detection rate forthese compounds in spite of the fact thetriazines are not particularly high usepesticides on P.E.I. Further comment onspecific studies of the triazines is notedlater in the report. It is worth notinghowever that this data comes from a verylimited number of stations (4 groundwaterand 4 surface water stations) and as suchmay not be very representative of Island-

wide conditions.

Aldicarb (TemikTM), an insecticide usedextensively in the past in potatoproduction was also found on a relativelyfrequent basis in groundwater samples inthe late 1980's, although the product is nolonger in use. Lindane and DDT residueswere both detectable in a reasonablenumber of fresh water samples andestuarine samples, with Lindane beingmore commonly detected in estuarinesamples and DDT being reported morefrequently in fresh water samples. Othercompounds detected on a less frequent,but not insignificant frequency in late1980's samples include carbophenothion,diazinon, disulfoton, heptachlor andimidan in groundwaters, and heptachlorand mirex in surface waters.

As noted above, it is difficult to discussthese results further in a meaningful way,without also addressing the context inwhich sampling programs have beendesigned and executed. Furthermore, thesampling efforts represented in Table 7cover a significant period of time, andcannot easily be used to assess currentconditions. It is beyond the scope of ageneral report such as this to go intodetail on the many projects representedby the data presented above, and a briefsummary of some of the key findings of anumber of these projects are presentedbelow. In addition, certain other works,not represented in the Envirodat database are included, where it is felt they willcontribute to the general understanding ofpesticide occurrences in P.E.I. waters.The reader is directed to the originalworks for more details on specific studies.


42

3.5.2 Summary of selectedprojects / reports onpesticide or other organiccompounds in P.E.I. Waters

1983-1992 Aldicarb studies

During the mid to late 1980's and early1990's several studies were conducted onthe occurrence and environmental fate ofthe highly toxic, and relatively solublecarbamate insecticide Aldicarb (Temik)(Matheson et al., 1987; Priddle et al.1987,Mutch et al. 1992). A farm well surveyconducted in 1983/1984 showed Aldicarb,to be present in 18% of high risk wellsaround potato fields. Subsequent fieldstudies suggested that the persistence ofaldicarb was related to cool soiltemperatures at the time of traditionalapplication, combined with inhibition ofproduct breakdown as a result of theoxidation of ammonia-based fertilizers.T h e r e s e a r c h r e s u l t e d i nrecommendations for product applicationaimed at reducing the persistence ofaldicarb, however by the early 1990's,Temik had been withdrawn from themarket.

An Assessment of Atlantic RegionWater Quality Branch Toxic ChemicalData 1980-1987 IW/L-AR-WQB-88-140 -O’Neill, 1988

This report synthesizes the results ofanalyses conducted by the EnvironmentCanada’s Water Quality Branch’s work ontoxic chemicals in the Atlantic regionbetween 1980 and 1988 and dealsprincipally with surface water samples.The report comments on results for fivechemical groups frequently reported inAtlantic region surface waters as well as

other less common parameters. Includedin the report are data for: organochlorineinsecticides including polychlorinatedbiphenyls (18 analytes), polynucleararomatic hydrocarbons (6), phthalic acidesters (14), organophosphorouspesticides (17), carbamate compounds(6), chlorinated benzenes (11),chlorophenoxy acid herbicides (3),triazine herbicides (3) and tri-aryl-phosphates (4). Organochlorineinsecticides and PCB’s received particularattention because of their previouswidespread use. The bulk of samplescollected from P.E.I. waters are from subbasin CB including principally the Dunkand Wilmot River systems.

Of the organochlorine insecticidesquantified, only alpha-BHC and lindane(gamma-BHC) were observed in surfacewaters at trace levels. DDT and itsisomers were the most commonly foundOC compound in lake (pond) sedimentsand was detected in stations from subbasin CB. Of the polynuclear aromatichydrocarbons (PAH’s) only fluoranthenewas detected in surface waters, althoughall 6 PAH’s quantified were detected insediment samples. PCB’s were notdetected in any Island waters.

Of the triazine herbicides, only atrazine isreported. It was observed in areas ofextensive agriculture, at levelscomparable to those seen in somestreams in Southern Ontario and Quebec.Carbamate pesticides were not detectedin surface water samples, although thereport notes that aldicarb and itsmetabolites have been detected ingroundwater on P.E.I.

Detection of chlorophenols, chlorinatedbenzenes, chlorophenoxy acids and tri-


43

aryl-phosphates are not indicated forP.E.I. waters, although reference is madeto infrequent observations of severalorganophosphorous pesticides in surfacewaters of the Atlantic region as a whole,albeit at levels at or slightly abovedetection limits. The detection of OPpesticides in groundwater is also noted,but is discussed in another report (seeAtlantic Region Federal-Provincial ToxicChemical Survey of Municipal DrinkingWater Sources 1985-1988 below).

Atlantic Region Federal-ProvincialToxic Chemical Survey of MunicipalDrinking Water Sources, DataSummary Report, Province of PrinceEdward Island, 1985-1988 -(Environment Canada, 1989)

The purpose of this survey was todescribe the current state of drinkingwater sources serving Atlantic CanadianMunicipalities, and included anexamination of over 150 parameters.Parameters included various in-use andpast-use pesticides, synthetic organicchemicals, volatile organic materials,metals, major ions, and physicalparameters. Thirty municipal watersupply sources were sampled on PrinceEdward Island. Highlights of the surveyare summarized below.

T h e s t u d y e xamined f i f t e e norganophosphorous compounds withcarbophenothion, phorate, disulfoton andmethyl parathion being reported atdetection limit concentrations in somesamples. Similar results were found forsamples in other provinces and wereattributed to sample contamination oranalytic interference.

Fourteen chlorinated phenols werequantified with only a few individualobservations of pentachlorophenol beingreported. The observations were notmatched in duplicate samples and all butone were at the detection limit. Themaximum concentration reported was0.007 �g/l. The maximum acceptableconcentration in drinking water is 60 �g/l.

Five carbamate pesticides werequantified with aldicarb and one of itsmetabolites being reported from severalwells. All observations were below the 9�g/l MAC for aldicarb. Seventeenorganochlorine compounds werequantified. Traces of heptachlor wereobserved on three occasions and tracesof lindane in a single sample.

With the exception of a single sample,polychlorinated biphenyls (PCB’s) werebelow the detection limit of 0.005 �g/l.The exception was a single sample fromSt. Eleanor’s well #2 at a level of 0.063�g/l. Subsequent sampling of this welldid not confirm this result. Samples fromthis same well also contained low levelsof PAH’s and CFC’s. It should be notedthat this well is not normally connected tothe distribution system, and is maintainedonly for back-up purposes.

Eleven chlorinated benzenes wereexamined, but all results reported wereless than the respective detection limits.Six PAH’s were quantified, with low levelsof fluoranthene being detected in nearlyall samples at ranges from 0.001 to 0.004�g/l. Similar results were seen in otherAtlantic Provinces. Four other PAH’swere reported at detection limit values ina single sample from St. Eleanor’s Well#2 as noted above, but were not reportedfrom a duplicate sample.


44

Over fifty volatile organic materials(VOM’s) were also quantified in thesurvey. Several VOM’s were detected attrace levels, although some of the samecompounds are also reported in blanksat comparable concentrat ions.Trihalomethanes (THM’s) were observedeither at levels close to the minimumquantitation limit (0.5 �g/l) or at tracelevels at the 9 sites having treatment(chlorination). Trichloroethene (TCE) andtetrachloroethene (PCE) and 1,21,2 -trifluorotrichloroethene (CFC-113) weredetected at low levels (maximumconcentrations of 1.6, 3.87 and 7.7 �g/lrespectively from a back-up well to theCharlottetown water supply). Results forwell #7 in Summerside reported amax imum leve l o f 4 . 8 �g/ ltetrachloroethene (PCE), and St.Eleanor’s well #2 reported 2.0 �g/ltrichlorofluoromethane (CFC-11). Allresults for VOC’s were below respectivedrinking water guideline levels.

Canada - P.E.I. Water ManagementAgreement Pesticide Sampling Project1988-1991

Between 1988 and 1991, groundwatersamples were collected from “high risk”wells in areas of active pesticide use.The surveys were conducted in twophases, the first examining the productsphorate, disulfoton, metribuzin andatrazine (Dinoseb analyses are alsoreported, but relate to investigation of aspecific pesticide spill) and includedsamples from 149 wells located within300 metres of treated fields. All fourpesticides were detected in the survey,with frequencies of detection ranging from2.7% for phorate and disulfoton to 11.7%for metribuzin. Atrazine, although only

examined at 9 sites due to its limited useon the Island, was detected in 4 wells. The second phase of the project wasmore limited in scope and reported onresults of 74 analyses from 43 wells foratrazine, mancozeb, chlorothalonil andmetribuzin. Each pesticide weredetected, with 13 samples reporting thepresence of one or more pesticideresidues. The frequency of detection forthis second phase of the project rangedfrom 33% for atrazine to 8% forchlorothalonil. Metribuzin was onlyexamined on 3 occasions but wasdetected in 2 of these samples. As in theprevious phase, all values were wellbelow respective health based drinkingwater guideline values.

A Screening Survey for ChlorothalonilResidues in Waters Proximal to Areasof Intensive Agriculture - (O’Neill etal., 1992)

This study was conducted in NewBrunswick and P.E.I., and includedsurface water and groundwater samplesas well as precipitation and tile fieldsamples. Only the tile drain work andsurface water samples were conducted inP.E.I., with a “once only” sampling runincluding 11 surface water stations ineastern Prince County, primarily in theDunk River and Wilmot River areas.Sampling was conducted during the peakgrowth and spray season and the samplesites were selected on the basis of morethan 50% the surrounding land use beingagricultural. Of eleven stations sampled,Chlorothalonil was detected only twice,once on a tributary to the Dunk river andonce on the Wilmot river (0.006 and 0.01�g/l respectively). The report notes that


45

the concentrations reported are in thesame order of magnitude as thosereported in precipitation collectors, andthe role of long range transport ofcontaminants is discussed briefly.

A Review of Triazine HerbicideOccurrence in Agricultural Watershedsof Maritime Canada 1983-1989 -(O’Neill and Doull, 1992)

In 1992, O’Neill and Doull reviewed heresults from various toxic chemicalstudies, providing a synthesis of data fortriazine herbicides in agriculturalwatersheds of Maritime Canada up untilearly 1989.

The data include results from a studyconducted in the Dunk River andSouthwest River watersheds, both areasof intensive potato production. Bothatrazine and metribuzin were included onthe parameter list. Metribuzin was notdetected in any of the 29 samples,however atrazine concentrations rangingfrom 0.011 to 0.017 �g/l were observed in13 samples. The authors noted thatatrazine was only detected in July, Augustand October samples, consistent with theuse pattern anticipated in the area.

In an 1986 survey in the Wilmot Valley 12surface water samples were all observedto contain atrazine at concentrationsbetween 0.016 and 0.032 �g/l.

Metalaxyl Contamination of GroundWater and Tile Drainage Water inAtlantic Canada - (Léger, D., 1996)

Selected farm wells in New Brunswickand P.E.I. were sampled four times

between 1994 and 1995 as part of abroader study examining potentialcontamination of groundwater and tiledrainage water by the systemic fungicidemetalaxyl. Samples were collected fromwells within 100 metres of fields that hadbeen treated with metalaxyl either in thecurrent year or in preceding years. Twoof the 21 P.E.I. wells consistently hadpositive metalaxyl concentrations: one inthe range of 0.07 to 0.25 ppb; the other inthe range of 10 to 25 ppb. The latter wellwas used for pesticide mixing and in alllikelihood contamination was due toaccidental release, but this was notconfirmed. All values were well below therecommended drinking water guideline of500 ppb.

Pesticide Residues in Sediment andWater from Two Watersheds in PrinceEdward Island, 1996 and 1997 -(Savard et al., 1999)

Several fish kills have occurred in westernPrince Edward Island in the last five yearsin an area of intensive potato production.Although the cause of one fish kill hasbeen attributed to a spill of pesticides, thecauses of the remaining fish kills has notbeen positively determined. In all but thespill case, these fish kills had beenpreceded by heavy rainfall events.Sampling on the Big Pierre Jacques andLong Rivers was conducted in 1996 and1997 to determine if pesticides wereentering these systems at concentrationsthat could present a risk to aquatic life.

Analytes included in the program includedChlorothalonil, Metribuzin, Dimethoate,Metalaxyl, Endosulfan, Azinphosmethyland Linuron. All of the analytesexamined were detected, with


46

frequencies of detection varying both byproduct and by rainfall amountsimmediately preceding individualsampling runs. The highest percentageof positive detections was 23% which wasfrom the sampling run conducted duringthe highest rainfall event of the samplingprogram, although no consistentcorrelation was found betweenprecipitation and the frequency ormagnitude of pesticide detections.Metalaxyl and metribuzin had the highestpercentage of positive detection at 23%,followed by chlorothalonil at 21%.Endosulfan was detected in 17% ofsamples, with the three remainingpesticides being detected in 8% ofsamples. On only one occasion was apesticide (chlorothalonil) detected atlevels in excess of published guidelinesfor the protection of aquatic life.

Pesticides in Groundwater survey1996-1998 - (Mutch, in preparation)

Over the period 1996 -1998 the P.E.I.Department of Technology & Environmentconducted a multi-faceted survey ofpesticide occurrence in groundwater(Mutch, in preparation). As an initial step,a comprehensive list of high andmoderate use pesticides were screenedaccording to their chemical properties andleaching potential, toxicity and usecharacteristics to prioritise tencompounds for field study. Samplingsites included 30 “high risk” wells in anintensive potato producing region and 30wells distributed across the Province, withemphasis on high capacity wells servicingsignificant portions of the population. Inaddition sites were targeted for samplingfor specific compounds, with 10 sites inthe vicinity of fields treated with a new

insecticide imidicloprid (Admire) and 10wells in the vicinity of blueberry fieldswere sampled for Hexazinone (Velpar)and Atrazine (Aatrax.). “High risk” wells inpotato producing areas were sampledtwice a year over the three year period,with the remaining sites being sampledonce per year.

With the exception of hexazinone, theresults of the survey were veryencouraging, with none of samplescollected from the 30 “high risk” sites orthe 30 “Island-wide” sites havingdetectable levels of any the 10 pesticidesselected via the screening process.Imidicloprid was detected at trace levelsin only one of the thirty samples collectedfor this product. In contrast, hexazinonein 14 of the 41 samples collected inblueberry growing areas. Seven of thesedetections were at trace levels between0.05 and 0.5 ppb, while the remainingseven detections ranged from 0.63 to8.10 ppb. All values were well below the210 ppb life time health advisory levelrecommended by the U.S. EPA.

A Survey of the Quality of MunicipalSupplies of Drinking Water fromGroundwater Sources in PrinceEdward Island - (Blundell and Harman,in preparation)

The Sierra Club of Eastern Canada andthe University of Waterloo jointlyconducted a survey of municipal watersupply wells on Prince Edward Islandduring the summer of 1998. The surveyincluded 18 sampling sites from 12 waterutilities across the Province. The studywas designed to provide a one time set ofanalytic results from municipal wellsacross Canada. The analytic results are


47

to be used to assess the quality ofgroundwater sources used for municipaldrinking water supply and to provide abaseline data base for water quality forsubsequent work. Two hundred andseventeen parameters were examined,including standard inorganic chemistry,metals, V.O.C.s and pesticides. Thepresence of agricultural activity in thevicinity of some well fields madepesticides an important parameter in thesurvey, and pesticides comprised 114 ofthe analytes examined in the survey.

In spite of the extensive list of analytes,not a single pesticide or metabolite wasdetected in any sample analysed. V.O.C.analyses detected a number oftrihalomethanes (THM’s) in treated watersupplies, although at very low levels(maximum concentrations in the range of0.0002 to 0.0006 mg/l for individualTHM’s), and trace levels of the THMchloroform was detected in raw watersamples from nine other wells. Alldetections were well below the currentdrinking water guideline value of 0.1 mg/l.

In addition to THM’s, a single detection oftrace concentrations (0.004 mg/l) oftetrachloroethene (PCE) was made in asample from one well in the City ofSummerside. Similar results have beenreported in previous surveys at this well,and all values have fallen well below the0.03 mg/l maximum acceptableconcentration recommended in theGuidelines for Canadian Drinking WaterQuality .

3.6 Faecal Coliform Bacteria

While the microbiological quality of wateris of interest principally for reasons of

public health, the focus of this section ison microbiological quality of surfacewaters and the associated constraints oncommercial shellfish harvesting andrecreational uses. While themicrobiological quality of drinking water isof obvious importance, on P.E.I., allpotable water supplies draw water fromgroundwater sources. In these casesbacterial quality relates more to theintegrity of the well or distribution systemrather than to the state of groundwaterquality as a whole. Because of the natureof the sampling points and the density ofthis water quality network, an adequateassessment of the integrity of watersupply systems from public healthperspective is not possible. As aconsequence, the bacterial quality ofgroundwater is not discussed further inthis report.

Faecal coliform bacteria are a group ofbacteria associated primarily with faecesof warm blooded animals and are used toindicate the possible presence ofpathogenic organisms which are harmfulto human health. Faecal coliformbacteria are used as an indicator by theCanadian Shellfish Sanitation Program(CSSP) for the determination of shellfishclosure areas. Faecal coliformcontamination is a serious problem for thewaterways and estuaries of the Provinceand approximately 83 shellfish growingareas are closed to harvesting due tofaecal coliform contamination.

Results for faecal coliform in freshwatersites are outlined in Table 8. The overallgeometric mean coliform concentrationfor the freshwater sites was 25MPN/100ml. The worst location, theClyde River, is located in the middle of acattle pasture.


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Table 8 Faecal Coliform Concentrations At Fresh Water Stations.

SampleLocation

River #samples

GeometricMean (MPN

/100ml)

% > 43 % > 260 % > 400

PE01CA0001 Mill(CarruthersBk)

30 31 43% 17% 13%

PE01CA0042 Miminegash 25 49 52% 36% 24%

PE01CA0043 Cains Brook 27 14 26% 11% 7%

PE01CB0001 Dunk 24 35 50% 4% 0%

PE01CB0005 Dunk(Breadalbane)

25 139 76% 24% 24%

PE01CB0141 Bradshaw 24 10 25% 4% 0%

PE01CB0143 Wilmot 25 42 56% 0% 0%

PE01CC0004 Winter 23 37 48% 13% 13%

PE01CC0010 Clyde 30 129 73% 37% 33%

PE01CC0213 West 28 60 57% 7% 7%

PE01CC0218 Hunter 23 24 43% 4% 0%

PE01CD0003 Morell 23 9 0% 0% 0%

PE01CD0050 Bear 22 23 18% 14% 5%

PE01CE0099 Montague 29 15 24% 0% 0%

PE01CE0101 Montague(Oceanview)

19 2 0% 0% 0%

PE01CE0100 Valleyfield 30 5 3% 0% 0%

There are no criteria for freshwater thatensure that the estuarine area into whichit discharges won’t be closed for shellfishharvesting. However, freshwaterconcentrations do provide insight as tothe sources of the faecal coliformconcentration in the estuary. For thosefreshwater sites that are close toestuarine waters, the geometric mean ofranges from 9 to 141 MPN/100ml. Thepercentage greater than 43 ranges from

0 to 73% of samples. While thesestreams don't represent all of thecontribution to the growing area, in theestuary below each of site, the estuarinearea has a shellfish closure with theexception of the Bear River whichdischarges directly to the Gulf of St.Lawrence and has not been assessed bythe CSSP. In each of the three estuariesthat are monitored in the annex network,there are shellfish closures. The


49

1 3 5 7 9 11 13Month

1

10

100

1000

Faec

al C

olifo

rms

(MPN

/100

ml)

Figure 23 Seasonal trends in freshwaterfaecal coliform concentrations.

freshwater stations in the network closestto these three estuaries have geometricmeans ranging from 14 to 141MPN/100ml. The percentage greaterthan 43 for each of these sites rangesfrom 24 to 73%.

Guidelines for recreational purposes (i.e.swimming, boating, etc.) are a geometricmean of 200 MPN/100ml for the site withno sample exceeding 400 (CCME, 1995).Thirty-four samples (8%) exceeded the400 MPN/100ml component of theguideline.

Faecal coliform counts are generally lowduring the winter months then increaseduring the spring to peak during latesummer (Figure 23). Bacteria countsthen decrease throughout the autumn.

Estuarine sites where the median orgeometric mean concentration of faecalcoliforms exceeds 14 MPN/100ml (MPN-Most Probable Number) or where morethan 10% of the samples exceed 43MPN/100ml for faecal coliforms areconsidered unsafe for the harvest anddirect consumption of shellfish. Faecalcounts in the estuarine waters of the

province are much lower than that of therivers and streams (Table 9). Thegeometric mean faecal coliformconcentration for the estuaries is 6MPN/100ml. There are only 192 recordsin the network for this parameter forestuarine waters, with 6% exceeding 43MPN/100ml, 1% exceeding 260MPN/100ml and 0% exceeding 400MPN/100ml. The upper estuarine stationin both the Mill and Montague Riversexceed shellfish growing criteria andmatch the closed classification for thearea in which they are located.

This is not the case for the upperestuarine station for the West Riverwhere the area is classified closed but thenetwork data meet the shellfish growingarea criteria. This is likely due to thenature of the regular samplingmethodology of the network.

It is important to again review theimportance of rainfall events on theresults obtained in the network data setdue to the nature of bacterialcontamination. It is often observed thatbacterial concentrations increase in areassubject to non-point sources of faecalcoliforms during and after rainfall events.Because the network sampling iscompleted utilizing a regular schedule ofapproximately six week intervals, thenetwork data set will probablyunderestimate the worst conditionsobserved in an estuary and its watershed.Normally, when shellfish closuredecisions are made under the auspices ofthe CSSP by Environment Canada, careis taken to ensure that the data setincludes adequate amounts of wetweather data. Readers should note thatas this data will not be utilized for thelocation of shellfish closures, this check


50

Figure 24 Seasonal trends in estuarinefaecal coliform concentrations.

Table 9 Faecal Coliform Concentrations At Estuarine Water Stations.

SampleLocation

River #Samples

GeometricMean(MPN

/100ml)

% > 43 % > 260 % > 400

PE01CA0047 Mill - upper 30 10 13% 3% 0%

PE01CA0015 Mill - mid 22 3 0% 0% 0%

PE01CA0048 Mill - lower 22 2 0% 0% 0%

PE01CC0214 West - upper 18 10 6% 0% 0%

PE01CC0113 West - mid 14 9 7% 7% 0%

PE01CC0092 West - lower 13 5 0% 0% 0%

PE01CE0105 Montague -upper

5 24 20% 0% 0%

PE01CE0103 Montague - mid 36 7 3% 0% 0%

PE01CE0104 Montague -lower

30 3 0% 0% 0%

has not been completed for this report.

Seasonal trends in faecal coliformconcentrations are also prominent inestuarine samples (Figure 24). As infreshwater samples, there is a prominentpeak in the middle of the year albeit amonth later in September. Unlike thefreshwater samples, there is also aprominent peak in the winter under theice. This is likely due to the influence ofstratification with fresher water occurringimmediately under the ice where thefaecal coliform samples are collected. Inthis fresher water, the concentration offaecal coliforms will more resemble thehigher concentrations found in freshwaterthan the lower ones in estuarine water.


51

4 Discussion andRecommendations

4.1 Key Findings

The water quality results discussed in thisreport indicate that the quality of thegroundwater supplies, fresh surfacewaters, and estuarine waters of theprovince is generally high, however, thereare a number of areas of concern, whichhighlight the need for further researchand attention.

Groundwater

With few exceptions, groundwater quality,as judged by the data presented in thisreport has generally been excellent. Thedata examined for this report containsonly a small number of cases of aparameter being measured at levels thatexceed those recommended in theGuidelines for Canadian Drinking WaterQuality.

A review of the major ion chemistry,shows the water to be relativelyconsistent in composition across theIsland, and while it would be consideredto be relatively hard, it is generally freeof any characteristics that would render itunusable for most domestic, industrial orcommercial purposes.

The presence of elevated sodium andchloride levels, often accompanied byexcessive hardness is perhaps the onemost notable departure from thisgeneralization. While in some cases thepresence of these salts is likely to be areflection of marine influences ongroundwater quality, it is equally likely that

a large number of these cases are aresult of the storage and use of salt forroad deicing.

Nitrate levels in groundwater are a sourceof concern. Although a relatively smallnumber of sampling stations (3%)reported results exceeding safe drinkingwater levels, data from other sourcesindicate that up to 7% of domestic wells insome agricultural areas of the Provincedo not meet the 10 mg/l nitrate-nitrogenstandard. Furthermore, because ofgroundwater’s substantial contribution, viabaseflow to Island streams and rivers, thenitrate content of groundwater can beexpected to play a significant role in thenutrient levels in surface water bodies.Unfortunately, nitrate levels that may below enough to be of no consequencefrom a drinking water perspective may behigh enough to still have a detrimentalimpact on surface water quality.

The metals content of P.E.I.groundwaters appears for the most part tobe determined by the native geology ofthe Province, and while all parametersmeasured were reported at detectablelevels, almost all fell well within healthbased drinking water guidelines.Typically, iron and manganese are thetwo metals most commonly found atelevated levels on P.E.I., although thedata base reviewed here shows that theaesthetic objectives were only rarelyexceeded, and not by a large margin.

Barium levels on the Island appear to berelatively high, a feature that is attributedto geological controls, although in all buta single instance, health based guidelinevalues were met.

Anthropogenic influences are suspected


52

with respect to the occasional values oflead in excess of recommended levels(leaching from plumbing fixtures).Anthropogenic sources are postulatedalso for arsenic, although in this case, thisconclusion is based more on the apparentabsence of natural sources, rather thanconclusive evidence of any specific man-made influence.

The contamination of groundwater byorganic chemicals, and in particularpesticides, is one of the more commonlyvoiced environmental concerns, andgroundwater analyses account for nearly65% of the pesticide data examined. Theresults confirm the fact that somepesticide compounds do leach to thewater table, but at the same time indicatethat this is a relatively uncommonoccurrence, with only 2.5% of the 5300groundwater pesticide analyses reportingdetectable concentrations. None of theanalyses in the database exceededrecommended maximum concentrationsfor drinking water.

One notable feature of the groundwaterpesticide data is the disproportionateoccurrence of specific compounds suchas the aldicarb or the triazine herbicides.For the triazines this is even moreremarkable considering the small numberof analyses conducted (21). While thepast detection of aldicarb is now nolonger an issue, it also serves tounderline the potential for highlyleachable compounds to impairgroundwater quality. Analyses of otherorganic compounds were rarely includedin the data base, however work publishedelsewhere (particularly surveys ofmunicipal drinking water supplies)indicates few influences of anthropogenicactivity on natural water quality.

Nonetheless, the detection of someorganochlorine compounds in some wellsunderscores the potential impact of landuse on groundwater quality.


Natural surface water quality on P.E.I. isgenerally excellent, and the generallycool, well oxygenated surface waters ofthe province supports a rich and diverseset of ecosystems. However the surfacewaters of the province, by their verynature, are subject to more diverseinfluences and uses than groundwaters,and this is reflected in the number ofwater quality issues associated withIsland streams, rivers and estuaries. Forthe most part these influences tend to befrom non-point sources, making thedevelopment of remedial strategies moredifficult.

Soil erosion, and the accompanyingsiltation of surface water bodies continuesto be one of the prime environmentalissues facing the Province. Turbidity andsuspended solids data generally fallwithin acceptable limits, however it isunlikely that this data, collected largely bygrab sampling, adequately represents themovement of sediment within the surfacewater environment. This is perhaps bestillustrated by the apparent absence in thedata, of evidence for seasonal variation insediment loads, when anecdotal evidenceindicates that a substantial portion ofsediment movement may occur overrelatively short “events”. As aconsequence, the data reported herecould be expected to seriouslyunderestimate the extent of the problem.The data do indicate a strong associationbetween sediment loads and adjacent


53

land use, consistent with conventionalwisdom on the topic. Nutrient enrichment of P.E.I. estuarineenvironments is a growing problem, andtoo often has implications for dissolvedoxygen levels as well. While much of theattention has been given to the role ofnitrogen in the development of eutrophicconditions in Island estuaries, there isevidence that phosphorous levels mayalso be significant, perhaps even limitingfactors in many of these cases (Meeuwig,1998).

The problem is complex, not onlybecause of the dynamic character ofestuarine waters, but also becausedifferent pathways may dominate themovement of nitrogen and phosphorous,even though the source of the nutrientsmay be similar. In the case of nitrogen, itis likely that the discharge of groundwatercontaining elevated levels of nitratecomprises a substantial, if not dominant,source of nitrogen to surface waterbodies. In contrast, phosphorous, whichis held well by the soil profile, may reachsurface water bodies in association withsediment rich run-off.

Results of pesticide analyses suggest thatlow levels of these compounds arecommonly detected in surface waters,however the concentrations reported arenormally well below the levels whichwould be expected to exert a significantnegative impact on aquatic life.Nonetheless the mid to late 1990's haveseen several fish kills, particularlyassociated with intense rain fall events inthe western part of the Province. Whilethese events have not been conclusivelylinked to the use of pesticides, theevidence does suggest that pesticides are

implicated in some way. If so, it alsosuggests that pesticides are enteringsurface water systems at concentrationsconsiderably higher than reported in thedata presented here, and that they arereaching these waters as a result ofnormal pesticide application practices.

The fact that apparently “lethal” levels ofthese compounds are not reported insurface waters may relate to the difficultyof capturing short term excursions inwater quality via the collection of grabsamples, in much the same way that itmay also be difficult to get trulyrepresentative indicators of sedimentmovement.

Bacterial contamination of surface watersalso remains a concern, with a significantportion of the Province’s shellfish growingareas closed to direct harvesting. As withnutrient enrichment and siltation, non-point sources are believed to besignificant contributors to the problem,hampering ef forts to improvemicrobiological quality of these waters.

While some metals have been observedexceeding fresh water guidelines at anumber of stations, the frequency ofexceedance at each station is very lowand not considered to be a concern.

4.2 Temporal Trends inWater Quality

It is the aim of this report to commentboth on the current quality of theProvince’s water resources, and onnotable changes in water quality. Withthe distribution and abundance of manywaterborne constituents being controlledby natural processes, only a few


54

parameters are expected to exhibitsignificant shifts over the short time frameof available data. Influences that aremost likely to be reflected in changes inthe environment are most likely to beman-made. It is not surprising thereforethat most of the data examined showslittle temporal variation, and that wherechanges are seen , such as for thenitrogen data, they are associated withwidespread anthropogenic activities. It isalso noted however, that the period ofrecord for many parameters is notparticularly great, and subsequentinvestigations may detect trends notclearly apparent in the existing data.

The data do suggest a subtle decrease insulphate and marginal increase in pH infresh surface waters of the Province.This may indicate an overall improvementof precipitation water quality for theProvince and may be an indicator of anoverall decrease in acid rain. In somewatersheds, slight increases in totaldissolved solids, mostly calcium,magnesium and bicarbonate (bicarbonateestimated from alkalinity data), haveaccompanied the increase in pH, howeverno explanation for this trend has offereditself at this time.

A comparable trend is not readily evidentin groundwater, however given residencetimes that are likely to range from years toseveral decades, and the dominatinginfluence of geology on major ionchemistry, it would not be expected toobserve such changes over the period ofrecord.

The most striking trend in the datahowever is for nitrogen in surface waters.As section 3.3 indicates, surface wateranalyses clearly exhibit substantial

changes in nitrogen concentrations, withnitrate levels doubling in some rivers overthe past two decades. Data from the MillRiver, Dunk River, and Morell River, whilee x h i b i t i n g d i f f e r i n g a b s o l u t econcentrations, each show increases innitrate over time. Unfortunately, datafrom existing groundwater stations is notparticularly useful in further illuminatingthese trends, although examination ofaggregate groundwater data from avariety of sources tends to support theassociation of elevated nitrateconcentrations with land use, and theincrease in nitrate levels over time. Thepredominance of site specific factors,including well construction, position in thewatershed, and in many cases very localland use, is responsible for these shortcomings.

Interestingly, the Dunk River data exhibitsa slight levelling off of nitrate levels,starting about the mid 1980's. It istempting to speculate on the significanceof this apparent change in trend,however, there is insufficient informationat this time to draw firm conclusions. Onepossibility is that nitrate inputs relating toland use, and nitrogen outputs asobserved in surface water, have reachedsome sort of steady state in thiswatershed. There are many uncertaintieshowever, particularly relating to theresidence time of nitrogen in thegroundwater portion of the system. Untilthese questions are resolved, it is difficultto predict what future nitrogen levelsmight be in the Island’s groundwater andsurface water systems. These trendshave important implications both for theavailability of safe drinking water, and forthe health of aquatic ecosystems acrossthe Province.


55

While the change in nitrogenconcentration in the three long-termfreshwater sites is the most well groundedin a continuous collection of samples, theapparent increase in estuarinephosphorus concentrations is alsodisturbing. Nevertheless, it would beexpected that if freshwater nitrogenloading to the estuaries is increasing, thatphosphorus loading would also beincreasing. While the freshwater samplecollection methods do not permit thistrend to be observed, it is likely that anincrease in freshwater phosphorusloading to the estuary must have occurredto result in an increase in concentration inthe estuary. The implication for resolvingeutrophication problems in P.E.I.estuaries is large. It is not likely thatreduction of either nitrogen loading norphosphorus loading alone would be anappropriate approach for remediation. Infact it may well be that both might have tobe reduced so as to not alter the ratio ofphosphorus and nitrogen in the estuary.As the primary form of nitrogen loading,nitrate, is soluble in water andphosphorus is largely bound to sediment,methods to reduce them may not be thesame.

The nature of the existing data onpesticides, and other organic compounds,do not readily allow interpretation oftemporal trends. The relatively lowfrequency of detection, the dependanceof results on the nature and intent ofindividual sampling programs, and thevarying emphasis over time on particularparameters, make it difficult to compareresults over significant periods of time.However, in-use pesticides can becommonly detected at low levels. Theoccurrence in the mid to late 1990's offish kills related to pesticide residues in

surface water are of major concern, but atthis point in our understanding of theproblem, conclusions on further trendswith respect to water quality cannot bedrawn.

Soil erosion has long been recognized asperhaps the most serious environmentalproblem on P.E.I., a point reinforced mostrecently by the report of the Round Tableon Resource Land use, however the datafrom the current network do not illustratea significant trend over time. This maysimply be an indication that soil lossescomparable to those seen today havepersisted over the available period ofrecord, or just as likely may be a functionof limitations in the manner in which datahas been collected.

4.3 Limitations of existingdata collection networkand recommendationsfor further work

This report is based on data collectedfrom a variety of sources, over aconsiderable period of time, and providesa useful review of water quality trendsand issues for the Province. Themechanisms in place for the collection ofthis data have evolved considerably overtime, and have developed into a wellintegrated monitoring system for keyelements of aquatic ecosystems onPrince Edward Island.

Much of this “re-alignment” took place inthe early 1990's through efforts such asthe “Evaluation and Planning of WaterRelated Networks on Prince EdwardIsland” (Environment Canada - P.E.I.Dept. Of Environment, 1991), and the


56

subsequent refinements to ecosystemmonitoring. In particular, the availabilityof data from all relevant media withinindividual systems, such as thoserepresented by the index basins andmanagement basins of the currentnetwork, provide much more meaningfulinformation than could be collected fromindividual “stand alone” stations. As thecomplexity of issues examined increases,it will be even more important to be ableto integrate information from severalmedia within individual systems, if we areto understand the linkages andrelationships between different portions ofthe environment. The current “alignment”of water quality stations, should alsogreatly improve the ability to evaluatewater quality data over time, providing acomprehensive, long term network ofstations, that will facilitate subsequentcomparative studies. Key to the ability totrack long term trends is the need tomonitor the same parameters at the samelocation for decades. At this time, onlytwo active stations have records in excessof ten years. Careful consideration mustbe made to the re-activation of historicalstations to aid in determining long termtrends.

Nonetheless, this review of data alsohighlights the limitations of this approachto data collection. It was noted in section3.3 that groundwater data for nitrogen, ascollected from a limited number ofstations, was of limited value inilluminating trends over time. Similarly,the evaluation of pesticides ingroundwater or surface water, because oftheir low frequency of detection, and inthe case of surface water samples, highly“event specific” nature is difficult toaccomplish with a limited number of“sentinel” type sampling stations. In

some cases, modifying the monitoringprogram to utilize continuous monitoringby probes will assist with this limitation. Inother cases it may be best to focusattention on periodic, specific researchprojects, which may examine certainphenomena in greater detail, or in thecase of groundwater, may involvecomprehensive surveys of much largernumbers of wells than the current networkcan provide. Toward this end, the “WaterManagement Initiatives” portion of thecurrent Federal - Provincial Water Annex,has played a vital role, providing underthis umbrella, the flexibility and resourcesneeded to address specific researchrequirements.

The accumulated data also suggests thatdiffering time frames could be employedfor different environments. Currentsampling involves collection ofgroundwater and surface water sampleson approximately 6 week intervals. Giventhe relatively long residence time ofgroundwater, the frequency of collectionat groundwater stations could be reducedsubstantially, without jeopardising thevalue of the data.

Semi-annual sampling, particularly iftimed with recharge and recessionperiods of the hydrologic year, wouldprovide more than adequate tracking ofmost trends that might be expected, andcould conceivably free up resources thatcould be used to advantage by anexpanded parameter list, or a largernumber of sampling stations. Forexample, recurring surveys of municipalwater supply wells for an extensive list ofparameters may provide more usefulinformation than the collection of up to 8samples per year from a limited numberof wells.


57

Special challenges for future sampling areposed by the need to more fullyunderstand the timing and magnitude ofpesticide residues and sediment enteringwaterways. In both cases, evidencesuggests that the most significant inputsare closely related to weather events, andin some cases, probably only isolatedgeographic regions. Continued work willbe required to address these needs.

Finally, the period of record representedin this review has seen many shifts inemphasis with respect to parameters ofconcern. While many of the parameterscurrently being reported are likely to be ofissue for the foreseeable future, other

parameters such as a number of metalsmay no longer be of the samesignificance as when they were initiallyproposed. For this reason, it may betimely to review data needs in light ofcurrent issues, and issues we cananticipate to be of importance in thefuture. While agricultural issues are likelyto dominate the water quality agenda forsome period of time, it might beopportune to examine, as an example,the growing field of climate changeresearch, and determine if changes to thecurrent suite of parameters could assist inevaluating this or other up-coming issues.


58

5 Acknowledgments

The authors would like to thank members of the Water Annex Management Committee fortheir support and guidance including C. Murphy (P.E.I. Dept. of Technology andEnvironment), D. Ambler, J. Keefe, J. Merrick, T. Pollock (Environment Canada). Thedata set for this report extracted from Environment Canada’s Envirodat. We would like tothank Dave Lockerbie for obtaining this large dataset and error correcting the extractionprocess to assure us of error free data. We also appreciate the efforts of those who havereviewed the drafts of this report. This survey could not have been completed without thefunding of: the Canada-P.E.I. Water Annex to the Federal/Provincial Agreement forEnvironmental Cooperation in Atlantic Canada, Environment Canada and HRDC ScienceHorizons Program and the P.E.I. Dept. of Technology and Environment.


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6 References

Bukowski, J., Somers, G., and Bryanton, J., 1997: Cigarette Smoking, Drinking WaterNitrates, and Other Potential Risk Factors for Adverse Reproductive Outcomes:Results of a Case Control Study on Prince Edward Island; Report to the P.E.I.Reproductive Care Program Inc.

Blundell, G., Harman, J., A, in preparation: Survey of Municipal Supplies of DrinkingWater from Groundwater Sources in Prince Edward Island, (in preparation);Survey and report conducted by the Sierra Club of Eastern Canada and theUniversity of Waterloo.

Canadian Council of Ministers of the Environment (CCME), 1987: Canadian WaterQuality Guidelines, Inland Waters Directorate, Ottawa

Environment Canada, 1989: Atlantic Region Federal-Provincial Toxic Chemical Surveyof Municipal Drinking Water Sources, Data Summary Report, Province of PrinceEdward Island, 1985-1988; Environment Canada Report IWD-AR-WQB-89-156

Environment Canada, 1998: Trends in Acid Deposition in the Atlantic Provinces (1980-1994); Environment Canada Website www.ns.doe.ca/aeb/ssd/acid/poster1.html

Environment Canada - Prince Edward Island Department of the Environment, 1991:Evaluation and Planning of Water Related Monitoring Networks on Prince EdwardIsland, Canada - P.E.I. Water Management Agreement report.

Gibb, J. and Jardine, D. 1991: Pesticide Sampling Project (to March 1990), Canada -P.E.I. Water Management Agreement Report. Pesticide Sampling Project (toMarch 1990), Canada - P.E.I. Water Management Agreement report.

Health Canada, 1996: Guidelines for Canadian Drinking Water Quality, 6th Edition,Publication 96-EHD-196

Larsen, P. And Somers, G., 1992: Pesticide Sampling Project (to March 1991), Canada -P.E.I. Water Management Agreement report.

Léger, D., Ernst, W., Julien, G.R.J., Boldon, M., Mutch, J.P., Kinnie, B., and Milburn,P., 1996, Metalaxyl Contamination of Ground Water and Tile Drainage Water inAtlantic Canada; Environment Canada report ECB-AR-ESD-96-193

Meeuwig, J.J., 1998: Eutrophication of the Mill River Estuary: Quantifying theContributions of Watershed Activities to Phosphorus Loading; � Cyber Consult,Study commissioned by the P.E.I. Department of Technology and Environmentand the Mill River Watershed Improvement Committee


60

Mutch, J.P., Jackson, R.E., Priddle, M.W. and Bray, D.I., 1992: The Fate andSimulation of Aldicarb in the Soil and Groundwater of Prince Edward Island;Environment Canada, Scientific Series No. 194, Rivers Research Branch,National Water Research Institute, Canada Centre for Inland Waters.

Matheson, R.A.F., R.M. Francis, W.R. Ernst, D.E. Jardine, M.N. Gill and P.A Hennigar,1987: Assessment of Prince Edward Island Groundwater for the PesticideAldicarb; Environment Canada Report EPS-5-AR-87-4

Mutch, J.P. (In preparation): Prince Edward Island Groundwater Pesticide MonitoringProgram (1996-1998); P.E.I. Dept. of Technology & Environment.

O’Neill, H.J., 1988: An Assessment of Atlantic Region Water Quality Branch ToxicChemical Data, 1980-1987; Environment Canada report IW/L - AR-WQB-88-140

O’Neill, H.J., Milburn, P., Léger, MacLeod, J. and Richards, J., 1992: A screeningSurvey for Chlorothalonil Residues in Waters Proximal to Areas of IntensiveAgriculture; Canadian Water Resources Journal, Vol. 17, No. 1, 1992

O’Neill, H.J. and Doull, J.A., 1992: A Review of Triazine Herbicide Occurrence inAgricultural Watersheds of Maritime Canada; 1983-1989; Canadian WaterResources Journal, Vol. 17, No. 3, 1992

P.E.I. Dept. of Fisheries and Environment and Environment Canada, 1996: Water onPrince Edward Island, Understanding the Resource, Knowing the Issues; Canada-P.E.I. Water Annex to the Federal/Provincial Framework Agreement forEnvironmental Cooperation in Atlantic Canada.

P. Lane and Associates Limited, 1991: Priorization of Prince Edward Island Estuariesfor Remediation; prepared for Environment Canada.

Priddle, M.W., Jackson, R.E., Novakowski, K.S., Denhoed, S., Graham, B.W.,Patteson, R.J., Chaput, D. And Jardine, D.. 1987: Migration and Fate ofAldicarb in the Sandstone Aquifer of Prince Edward Island; Water Poll. Res. J.Canada, Volume 22, No. 1, 1987

Round Table on Resource Land Use and Stewardship, 1997: Cultivating Solutions,Queens Printer, Charlottetown, P.E.I.

Savard, M.A. Julien,G.R. J., MacLean, B., Raymond, B., and Doull, J., 1999: PesticideResidues in Sediment and Water from Two Watersheds in Prince Edward Island,1996 and 1997; Environment Canada Surveillance Report EPS-5-AR-99-2,Atlantic Region.


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Somers, G.H., 1998: Distribution and Trends for Occurrence of Nitrate in P.E.I.Groundwaters; Proceedings, Nitrate-Agricultural Sources and Fate in theEnvironment - Perspectives and Direction, Charlottetown, P.E.I. pg 19-26,Published by Eastern Canada Soil and Water Conservation Centre, Saint André(Grand Falls), N.B.

Somers, G.H., (in preparation): abstract in Proceedings of a Nitrate Workshop February1999 hosted by the Bedeque Bay Environmental Management Association.

Swain, A., 1995: Well Watch; Report prepared for the Bedeque Bay EnvironmentalManagement Association.

Thompson, G.R., 1998: The Role of Vegetated Buffers in Reducing Agricultural Impactson Prince Edward Island Surface Waters - A Review; prepared for Canada -Prince Edward Island Water Annex to the Federal Provincial FrameworkAgreement for Environmental Cooperation in Canada


62

Appendix 1 Annex Water Quality Stations

Station Name Latitude LongitudePE01CA0001 Mill River at Wsc Gauge in Bloomfield Park 46.744167 -64.181667PE01CA0015 Mill River Estuary About 5 km SW of Alberton 46.770278 -64.114167PE01CA0041 Mill River 600 M E of Hwy 12 Bridge 46.775278 -64.110000PE01CA0042 Miminegash River Near St. Lawrence 46.849167 -64.196667PE01CA0043 Cains Brook Near Bloomfield Corner 46.754444 -64.181667PE01CA0044 Bloomfield Mall Washroom From Washroom Sink 46.768333 -64.177222PE01CA0045 Bloomfield Elementary School From Water Tank 46.765556 -64.189444PE01CA0046 Hernewood Junior High School 46.735556 -64.173333PE01CA0047 Mill River Estuary at Mill R. Provincial Park Dock 46.750556 -64.166389PE01CA0048 Mill River Estuary Near Fox Point 46.766667 -64.073889PE01CB0001 Dunk River at Waugh Road 46.345556 -63.632778PE01CB0005 Dunk River at Hwy 231 Bridge, Breadalbane 46.356111 -63.502500PE01CB0115 Summerside Town Well 7 46.415833 -63.778056PE01CB0141 Bradshaw River at Central Bedeque 46.331389 -63.716944PE01CB0142 Bedeque Senior Citizens Home From Laundry Room Tap 46.338333 -63.726389PE01CB0143 Wilmot River Near Kelvin Grove 46.393333 -63.658611PE01CB0144 Well at Gary Woodworth'S House, Stanchel, PEI 46.328889 -63.474722PE01CC0004 Winter River Near Pleasant Grove 46.335833 -63.106667PE01CC0010 Clyde R. About 1.5 km North of Clyde R. (Hwy 247) 46.236944 -63.262500PE01CC0042 Winter River South Branch at Union Road Culvert 46.312500 -63.128056PE01CC0059 Charlottetown - Union A 46.314167 -63.123889PE01CC0092 Charlottetown Hbr--West River Estuary 46.210833 -63.159444PE01CC0113 West (Eliot) River 770 M East of Dickieson'S Pt. 46.190278 -63.227778PE01CC0180 Charlottetown Water Supply - Brackley Well #9 46.314167 -63.150000PE01CC0213 West River at Riverdale 46.230833 -63.351389PE01CC0214 West River at Dunedin 46.198056 -63.296667PE01CC0218 Hunter River Below Bell Pond at Bridge 46.394167 -63.343889PE01CC0220 Cornwall Well (G. Somers) 46.226111 -63.217778PE01CD0003 Morell River From Road Bridge 46.362778 -62.703056PE01CD0047 Morell Senior Citizens Home Unit B 46.414722 -62.703889PE01CD0048 Compton Farms Near Bangor 46.374444 -62.681944PE01CD0049 North Lake Creek Near Lakeville 46.449722 -62.122222PE01CD0050 Bear River at St. Margarets 46.453056 -62.382500PE01CE0096 Montague River Near Robertson 46.176389 -62.610000PE01CE0099 Montague River Above Knox Pond 46.149722 -62.696944PE01CE0100 Valleyfield River Near Kilmuir 46.138611 -62.678056PE01CE0101 Montague River at Ocean View 46.068611 -62.813333PE01CE0102 Montague Senior Citizens Home Unit G 46.166944 -62.644722PE01CE0103 Montague River Estuary Near Dewars Point 46.171667 -62.616389PE01CE0104 Montague River Estuary Near Lower Montague 46.174167 -62.561944PE01CE0105 Montague River Estuary Near Montague 46.163889 -62.648611


63

Appendix 2 Historical Water Quality Stations

Station No Station Name Lat LonPE01CA0002 Carruthers Brook (Mill River) at Hwy 143 Bridge 46.720556 -64.271667PE01CA0003 Profitts Pond at Outlet 46.783333 -64.166667PE01CA0004 Kildare River Estuary in Centre of Channel 46.866389 -64.066667PE01CA0005 Kildare River Estuary in Centre of Channel 46.863056 -64.065278PE01CA0006 Kildare River Estuary in Narrowest Channel 46.856944 -64.063611PE01CA0007 Huntley River Estuary in Centre of Channel 46.851111 -64.064722PE01CA0008 Kildare River Estuary in Centre of Channel 46.849722 -64.054167PE01CA0009 Kildare River Estuary in Centre of Channel 46.836944 -64.051667PE01CA0010 Kildare River Estuary in Centre of Channel 46.832500 -64.045000PE01CA0011 Kildare River Estuary in Channel, SE of Causeway 46.829167 -64.031667PE01CA0013 Kildare River Estuary in East Shore Channel 46.814722 -64.036667PE01CA0016 Tignish River Estuary From Hwy 135 Bridge, Tignish 46.939444 -64.029722PE01CA0017 Miminegash River Estuary From Hwy 14 Bridge 46.858056 -64.223889PE01CA0018 Trout River at Carleton From Hwy 2 Bridge 46.693056 -64.153056PE01CA0020 Mill River Below Hwy 12 Bridge, Center of Estuary 46.776944 -64.105278PE01CA0022 Gulf of St. Lawrence ~ 300 M SE of Kildare Point 46.801944 -64.030000PE01CA0024 Smelt Creek Estuary at Confluence of Bideford R. 46.616944 -63.915000PE01CA0026 Kildare River Estuary in Centre of Channel 46.871944 -64.074444PE01CA0027 Kildare River Estuary in Centre of Channel 46.868611 -64.067778PE01CA0034 Arsenaults Pond 46.950000 -64.066667PE01CA0035 Leards Pond at Trout River 46.691667 -64.205556PE01CA0036 Mill River at Mill River Provincial Park 46.736389 -64.163611PE01CA0037 Mill River Near Bloomfield Corner 46.747778 -64.165000PE01CA0038 Mill River at Fortune Cove 46.760833 -64.135278PE01CA0039 Mill River at Mill River East 46.762500 -64.140556PE01CA0040 Mill River Near Cascumpec 46.771944 -64.091667PE01CA0049 Big Pierre Jacques River, Upper 46.656944 -64.342500PE01CA0050 Big Pierre Jacques River, Middle 46.656111 -64.342222PE01CA0051 Big Pierre Jacques River at Bridge 46.652778 -64.339722PE01CA0052 Drainage Ditch Near Miscouche 46.556667 -64.018056PE01CA0053 Unnamed Brook 46.657222 -64.032222PE01CA0054 Long Creek 46.786667 -64.200278PE01CB0002 Scales Pond 100 M Above Dam \Center 46.346389 -63.608611PE01CB0003 Summerside Hbr., Bedeque Bay, West of Indian Head 46.370556 -63.831944PE01CB0004 Paynters Pond at Outlet. 46.487500 -63.545833PE01CB0006 Dunk River 1.6 km West of Breadalbane 46.355000 -63.490000PE01CB0007 Summerside Harbour, Bedeque Bay 46.364167 -63.816944PE01CB0008 Summerside Harbour About 198m North of Indian Head 46.388889 -63.813889PE01CB0009 Summerside Harbour,Bedeque Bay, WNW of Grahams Pt. 46.346111 -63.845556PE01CB0010 Summerside Harbour, Miscouche Cove 46.395278 -63.870000PE01CB0011 Summerside Harbour Estuary of Dunk River 46.363611 -63.787778PE01CB0012 Summerside Harbour Estuary of Dunk River 46.352222 -63.753056PE01CB0013 Summerside Harbour Estuary of Dunk River 46.360556 -63.766944PE01CB0014 Scales Pond at Unnamed Tributiary 46.340000 -63.605278PE01CB0015 Scales Pond 600 M Above Dam at Center 46.345556 -63.604167PE01CB0016 Scales Pond Above Dam 46.350833 -63.594722PE01CB0017 North Brook (Lloyds Brook) South of South Freetown 46.345833 -63.631944PE01CB0018 Wilmot River Near Wilmot Valley 46.393333 -63.658611PE01CB0019 Dunk River at Lower Bedeque 46.340556 -63.668889PE01CB0020 De Sable River Ne of Hampton 46.226667 -63.438889


Station No Station Name Lat Lon

64

PE01CB0023 Westmorland River East of Crapaud at Hwy 13 Bridge 46.236667 -63.479444PE01CB0025 Unnamed River North of Augustine Cove Below Dam 46.229167 -63.606389PE01CB0026 Unnamed R. at Road Bridge 100m N of Cape Traverse 46.242778 -63.640000PE01CB0030 Barbara Weit River at Hwy 2 Bridge 46.425278 -63.677222PE01CB0038 Summerside Harbour Estuary of Dunk & Wilmot Rivers 46.391667 -63.802222PE01CB0040 Dunk River Below Scales Pond at Hwy. 109 46.341667 -63.610556PE01CB0041 Southwest Brook 50 M Above Middleton Pond 46.317778 -63.624722PE01CB0042 Southwest Brook at Outfall of Middleton Pond 46.321944 -63.623889PE01CB0043 Wilmot River at Outfall of Ducks Unlimited Pond 46.401111 -63.628056PE01CB0044 Wilmot River 350 M Below Hwy 109 46.399167 -63.631667PE01CB0045 Upstream Background Site: Pestfund 1988 46.250000 -63.623889PE01CB0046 Inlet To Pond Pestfund Project 1988 46.246667 -63.626944PE01CB0047 Outlet From Pond 25 M Downstream:Pestfund 1988 46.245833 -63.628333PE01CB0048 Dunk River at Outflow of Scales Pond 46.343611 -63.609444PE01CB0050 Pond Pestfund 1988 Study Site Unnamed 46.246389 -63.627778PE01CB0053 Marchbanks Pond On The Wilmont River 46.395000 -63.693056PE01CB0060 Summerside Hbr., Bedeque Bay, South of Phelan Pt. 46.381389 -63.853056PE01CB0067 Summerside Harbour Estuary of Dunk & Wilmot Rivers 46.384167 -63.811389PE01CB0069 Summerside Harbour Estuary of Dunk & Wilmot Rivers 46.388056 -63.809444PE01CB0074 Middleton Pond at Depression, 200 M Above Dam 46.320000 -63.625556PE01CB0075 Malpeque Bay 1850m.S.61 W.From Boat Launching Site 46.466667 -63.766667PE01CB0080 Summerside Harbour at Wilmot River Estuary 46.390556 -63.740556PE01CB0082 Summerside Harbour 46.383333 -63.783333PE01CB0084 New London Bay 1200 M E of McEwens Island 46.494167 -63.464167PE01CB0102 Barbara Weit River Estuary From Road Bridge 46.431389 -63.685833PE01CB0108 Dunk River Estuary at Hwy 110 Bridge 46.340556 -63.667778PE01CB0112 Summerside Harbour, Colville Bay 46.362222 -63.766944PE01CB0135 Pond On Property of L. Huestis, Hwy 107 46.408333 -63.688056PE01CB0136 Wilmot River at Hwy 110 Adjacent To Wsc Gauge 46.393611 -63.659167PE01CB0137 Emerald Brook Near Emerald 46.360000 -63.557500PE01CB0138 Elmo River 1 km West of Newton On Route 111 46.338611 -63.596389PE01CB0139 Unnamed Stream 1.22 km South of Lower Freetown 46.352222 -63.667778PE01CB0140 Wrights Pond 46.333333 -63.716667PE01CB0188 Wilmot River 46.393056 -63.659722PE01CC0002 North (Yorke) River at Hwy 258 Bridge 46.300556 -63.221944PE01CC0006 O'Keefe Lake (Boat Launching Site) at Hwy 5 46.247778 -62.818333PE01CC0007 Moss Lake 46.231667 -62.913056PE01CC0008 Weisner'S Pond 46.264167 -62.886389PE01CC0009 Glenfinnan Lake at South Shore of Lake 46.294444 -62.955000PE01CC0011 Hardys Pond (Winter River#Near Boat Ramp) 46.335278 -63.107778PE01CC0016 Winter (Chapel) Creek From Hwy 6 Bridge 46.414167 -63.290000PE01CC0017 Clyde River 1070 M North of Clyde River Mouth 46.202500 -63.261667PE01CC0027 West River 1.3 km East of Tch. Bridge, Bonshaw 46.200833 -63.336944PE01CC0029 West (Eliot) River 320 M SW of Dickieson'S Point 46.187500 -63.240000PE01CC0032 Hunter River Estuary in Channel Centre 46.443056 -63.303889PE01CC0033 Hunter River Estuary 1080 M West of Lighthouse 46.455000 -63.308056PE01CC0034 Hunter River Estuary 270 M West of Lighthouse 46.455556 -63.296389PE01CC0035 Hunter River Estuary About 225 M SW of Lighthouse 46.452778 -63.292778PE01CC0036 West (Eliot) River From Hwy 13 Culvert, Brookvale 46.283611 -63.408056PE01CC0037 West (Eliot) River at Crosbys Mill 46.205556 -63.351944PE01CC0038 Lake of Shining Waters Outlet From Hwy Bridge 46.498056 -63.391667PE01CC0039 Winter River @ Bridge Behind Union Pumping Station 46.313889 -63.123333PE01CC0040 Wrights Creek 500m Above Andrews Pond 46.280278 -63.115556



65

PE01CC0041 Charlottetown Hbr 175 M South of PEI. 46.226667 -63.126667PE01CC0044 Unnamed Tributary 46.312778 -63.123889PE01CC0045 Hunter River at Outfall of Bagnalls Pond 46.359167 -63.348889PE01CC0046 Hunter River at Outfall of Bells Pond 46.394167 -63.344444PE01CC0047 West (Eliot) River Estuary at Hwy 1 Bridge 46.196111 -63.350556PE01CC0048 Charlottetown Hbr 710 M NW of Battery Point 46.211667 -63.136389PE01CC0055 West River at Center at Confluence of Ferguson Ck. 46.201389 -63.188889PE01CC0056 North River at Center 100 M Above Cable Crossing 46.233611 -63.156111PE01CC0062 Gulf of St. Lawrence About 1440 M NE of Lighthouse 46.462500 -63.279167PE01CC0064 Charlottetown Harbour at Hillsborough River 46.246944 -63.094444PE01CC0068 Charlottetown Hbr-Hillsborough Estuary 46.236389 -63.111667PE01CC0074 Charlottetown Hbr 150 M East of Texaco Terminal 46.230556 -63.119167PE01CC0075 Lake Verde 150 M From South End of Lake 46.238056 -62.884444PE01CC0076 Charlottetown Hbr. About 1350 M W of Ferry Point 46.225278 -63.124444PE01CC0079 Charlottetown Harbour 46.216667 -63.116667PE01CC0082 Charlottetown Hbr. About 1800 M W of Ferry Point 46.226389 -63.135000PE01CC0086 Charlottetown Hbr-North River Estuary 46.225556 -63.152778PE01CC0087 Charlottetown Hbr.,North R. Estuary (Hwy 1 Bridge) 46.256667 -63.183889PE01CC0090 Charlottetown Hbr--West River Estuary 46.193611 -63.205000PE01CC0095 Hatchery Pond Near Outlet Southport Prov. Park 46.215556 -63.101111PE01CC0096 Charlottetown Hbr. About 0.80 km N of Alchorn Pt. 46.203611 -63.133889PE01CC0100 Charlottetown Hbr. 1350 M South of Old Battery Pt. 46.216111 -63.139722PE01CC0102 Mackinnons Pond at Left Bank Near Outfall 46.412778 -62.746667PE01CC0104 West (Eliot) River 1080 M East of Causeway 46.189167 -63.220278PE01CC0108 West (Eliot) River 240 M East of Causeway 46.191389 -63.230278PE01CC0110 West (Eliot) River 220 M East of Causeway 46.191389 -63.236667PE01CC0112 West (Eliot) River 760 M South of Dickieson'S Pt. 46.184167 -63.240556PE01CC0119 Long Creek 550 M South of Long Creek Mouth 46.182778 -63.262778PE01CC0120 West (Eliot) River 1.2km SE of Bridge, Dunedin 46.191667 -63.277778PE01CC0123 West (Eliot) River 140m West of Bridge 46.200278 -63.288889PE01CC0125 West (Eliot) River 750m West of Bridge 46.196667 -63.296389PE01CC0127 West(Eliot)River 1610m West of Bridge, Dunedin 46.190833 -63.270556PE01CC0130 West River 4 km East of Tch. Bridge,Bonshaw 46.208056 -63.331667PE01CC0144 Rustico Bay in Centre of Channel 46.439167 -63.272500PE01CC0145 Rustico Bay About 720 M Ne of Grand Pere Point 46.425278 -63.234167PE01CC0148 Hillsborough River Estuary 72 M NE of Oil Tanks 46.243056 -63.103889PE01CC0151 Hunter River Estuary From Hwy 224 Bridge 46.408889 -63.348056PE01CC0155 Charlottetown Harbour 325 M WNWof Rosebank Point 46.221667 -63.120278PE01CC0158 Charlottetown Harbour at North Creek 46.251667 -63.155556PE01CC0159 Charlottetown Harbour Centre 46.214722 -63.150278PE01CC0162 Charlottetown Harbour Mouth 46.191944 -63.125278PE01CC0166 Wheatley River Estuary From Hwy 224 Bridge 46.372778 -63.288889PE01CC0168 North (Yorke) River Estuary From Causeway Gates 46.256111 -63.184722PE01CC0206 Officers Pond 46.329167 -63.075000PE01CC0207 West River at St. Catherines 46.200000 -63.288611PE01CC0208 West River at Dunedin 46.200556 -63.288611PE01CC0209 West River Near Meadowbank 46.188333 -63.232500PE01CC0210 West River at Meadowbank 46.193333 -63.229722PE01CC0211 West River Near Rocky Point 46.203333 -63.161389PE01CC0212 West River Near York Point 46.215000 -63.174167PE01CC0219 S.B. Winter River Near Charlottetown Airport 46.296389 -63.133611PE01CC0221 Clarks Pond, Natural Seepage Inlet Area 46.397778 -63.403889PE01CC0222 Clarks Pond, Middle 46.398889 -63.400000



66

PE01CC0223 Clarks Pond Near Outlet 46.365556 -63.396667PE01CC0224 Lake of Shinning Waters Outlet 46.398611 -63.390556PE01CC0225 Lake of Shinning Waters 46.396389 -63.388333PE01CC0226 Green Gables Pond 46.390278 -63.380556PE01CC0227 Campbells Pond Outer Basin 46.411667 -63.060556PE01CC0228 West River 46.230556 -63.351944PE01CD0007 Souris River 260 M Nnw of Hwy 2 Bridge 46.358889 -62.279722PE01CD0008 Colville Bay Entrance 470 M Se of Souris Head 46.331944 -62.275278PE01CD0015 Morell River, East Branch From Road Bridge 46.302778 -62.674722PE01CD0018 Boughton River From Road Bridge 46.320000 -62.534167PE01CD0022 West Branch Morell River at Hwy 320 Bridge 46.303611 -62.762222PE01CD0023 Colville Bay About 75 M SW of Knight Point, Souris 46.345833 -62.248333PE01CD0025 Colville Bay About 110 M SE of Breakwater Beacon 46.347222 -62.254167PE01CD0028 Colville Bay About 7 km NE of Lobster Pt., Souris 46.351667 -62.266667PE01CD0033 Colville Bay About 450 M NW of Lobster Pt., Souris 46.351667 -62.277500PE01CD0034 Mooneys Pond at Outlet 46.292222 -62.770278PE01CD0037 Colville Bay About 2 km SE of Souris Head 46.329167 -62.257778PE01CD0039 Colville Bay About 30 M West of Breakwater Beacon 46.346944 -62.256667PE01CD0040 Colville Bay Entrance 420 M SE of Swanton Point 46.338889 -62.243889PE01CD0041 Souris Harbour Inside Fisherman's Wharf 46.348889 -62.250278PE01CD0051 Morell River 46.317500 -62.749444PE01CE0001 Brudenell River 1km Below Hwy 4 Bridge (Wsc Gauge) 46.199722 -62.648889PE01CE0002 Knox Pond On The Montague River 46.157500 -62.679444PE01CE0003 Cardigan Bay Estuary of Cardigan River 46.224167 -62.588056PE01CE0004 Orwell River at Uigg 46.164167 -62.813889PE01CE0005 Cardigan Bay,Georgetown Hbr. 530m NE of Aitken Pt. 46.173056 -62.543611PE01CE0012 Murray Harbour About 350 M Ne of McInnis Point 46.042778 -62.529167PE01CE0015 Sturgeon R. Above McKinnon Pond at Hwy 317 Bridge 46.113889 -62.570833PE01CE0021 Pinette River Estuary Centre Fork 46.071944 -62.902500PE01CE0022 Pinette River Estuary 800 M Below Dam 46.079444 -62.888611PE01CE0023 Cardigan Bay Estuary of Montague River 46.168611 -62.620278PE01CE0024 Montague River Estuary From Hwy 4 Bridge 46.163889 -62.648056PE01CE0025 Cardigan Bay Estuary, Georgetown Harbour 46.163056 -62.517222PE01CE0027 Cardigan Bay at Mouth of Brudenell River 46.183056 -62.555278PE01CE0028 Cardigan Bay at Mouth of Montague River 46.174722 -62.559444PE01CE0029 Murray River 320 M NNE of Hwy 4 Bridge 46.016111 -62.609167PE01CE0030 Murray River 2.2 km NNE of Hwy 4 Bridge 46.021667 -62.581667PE01CE0031 Murray River 420 M South of Fairchild Point 46.032778 -62.536389PE01CE0032 Murray Harbour at Greek River 670m W of Indian Pt. 46.042222 -62.529167PE01CE0033 Murray Harbour 950 M E of N Tip of Reynolds Island 46.040556 -62.503056PE01CE0034 Murray Harbour 360 M NE of Sharams Point 46.024167 -62.520278PE01CE0035 Murray Hbr Estuary of Fox River 46.020000 -62.520556PE01CE0036 Murray Hbr Estuary of South River 46.008056 -62.521667PE01CE0037 Murray Harbour Estuary of South River 46.018333 -62.502778PE01CE0038 Murray Harbour (Poverty Beach) 46.019167 -62.485556PE01CE0039 Northumberland Strait 2.6 km NNE of Murray Head 46.040556 -62.441389PE01CE0040 Valleyfield River Estuary From Hwy 326 Bridge 46.155000 -62.653611PE01CE0042 Murray Hbr Estuary 2 km ENE of Indian Point 46.046389 -62.493889PE01CE0043 Murray Hbr Estuary In Channel 46.025556 -62.502778PE01CE0044 Northumberland Strait off Cardigan Bay 46.161944 -62.391389PE01CE0047 Cardigan Bay Estuary of Brudenell River 46.202500 -62.609722PE01CE0048 Northumberland Strait About 2 km N of Murray Head 46.035278 -62.454167PE01CE0053 Montague River Above Hwy 320 Bridge 46.157778 -62.679444



67

PE01CE0054 Stewarts Pond at Outlet 46.141667 -62.550000PE01CE0055 Cardigan Bay, Cardigan River Mouth 46.200278 -62.501389PE01CE0058 Cardigan Bay 30 M South of Cardigan Point 46.173056 -62.496667PE01CE0061 Georgetown Harbour About 495m N of St. Andrews Pt. 46.168611 -62.529167PE01CE0067 Murray R. Estuary About 2.6 km Below Hwy 4 Bridge 46.021389 -62.582778PE01CE0069 Murray River Estuary About 1.1km E of Pleasant Pt. 46.032222 -62.536944PE01CE0071 Murray Harbour About 700 M North of Cherry Island 46.040833 -62.503889PE01CE0072 South River Estuary In Centre of Channel 46.001944 -62.528611PE01CE0076 South River Estuary In Centre of Channel 46.012222 -62.512778PE01CE0078 Murray Harbour Channel About 165m S of South Point 46.018889 -62.454444PE01CE0079 Murray Harbour About 315 M NE of Sharams Point 46.024167 -62.520278PE01CE0080 Pinette River Estuary 75 M Above Tch. Causeway 46.061667 -62.906389PE01CE0084 Cardigan Bay Estuary of Montague River 46.166389 -62.634722PE01CE0086 Georgetown Harbour In Center of Channel 46.166944 -62.526944PE01CE0091 Murray Harbour About 400 M East of Machon Point 46.017778 -62.501944PE01CE0093 Montague River at Montague - 400 M E of Wharf 46.166111 -62.640000PE01CE0094 Montague River at Montague - 850 M NE of Wharf 46.168333 -62.634722PE01CE0095 Montague River at Dewar Point 46.170556 -62.616667PE01CE0097 Montague River at Lower Montague 46.169722 -62.566667PE01CE0098 Montague River Near Brudenell 46.181111 -62.569167PE01CE0106 Brudenell River 46.201944 -62.656389

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