Narragansett Bay Narragansett Bay Environmental Environmental

MonitoringMonitoring

Li-Ling YangLi-Ling Yang

Roger Williams UniversityRoger Williams University

Research FocusResearch FocusWhat are seasonal fluctuations of

nitrate in Narragansett Bay and the processes that may affect these fluctuations?

ContextContext::Brief History of Narragansett Brief History of Narragansett

BayBay1901- The Providence Sewage Treatment 1901- The Providence Sewage Treatment

System is put into operation.System is put into operation.1910- Providence's sewage treatment 1910- Providence's sewage treatment

plant begins to run into problems due to plant begins to run into problems due to inadequacies of the chemical inadequacies of the chemical precipitation process and the precipitation process and the continuing growth of the City. continuing growth of the City.

1970's- In the absence of a continuous 1970's- In the absence of a continuous maintenance program, the condition of maintenance program, the condition of the Field Point plant declines to the the Field Point plant declines to the point where nearly 65 million gallons of point where nearly 65 million gallons of untreated or partially treated sewage untreated or partially treated sewage flow into Rhode Island waters everydayflow into Rhode Island waters everyday

ContextContext (Cont’d) (Cont’d) Brief History of Narragansett Bay Brief History of Narragansett Bay

(Cont’d)(Cont’d)1973- The US EPA orders the City of 1973- The US EPA orders the City of

Providence to address the chronic Providence to address the chronic pollution problem associated with the aged pollution problem associated with the aged Field Point WWTF and CSO discharges, Field Point WWTF and CSO discharges, which violate the Clean Water Act.which violate the Clean Water Act.

1979- Governor Garrahy creates a 1979- Governor Garrahy creates a Governor's Sewerage Facilities Task Force Governor's Sewerage Facilities Task Force to address the EPA mandates.to address the EPA mandates.

1999-2001- RIDEM reviews and approves 1999-2001- RIDEM reviews and approves the NBC Combined Sewer Overflow the NBC Combined Sewer Overflow Abatement Plan, a 3-phase, 20-year Abatement Plan, a 3-phase, 20-year comprehensive project to end CSO comprehensive project to end CSO discharges into Upper Narragansett Bay. discharges into Upper Narragansett Bay. 

Context:Context: Significance of Monitoring Significance of Monitoring

Narragansett Bay Nutrient Narragansett Bay Nutrient Concentrations and Water qualityConcentrations and Water quality Tidal wetlands are dynamic ecosystems of

high biological productivity that provide essential habitats for fish, birds, amphibians and many species of invertebrates. However, they are among some of the ecosystems most affected by human activities.

Narragansett Bay, a bay and estuary on the north side of Rhode Island Sound which forms New England's largest estuary, is one such example.

Successful restoration and preservation efforts therefore require a careful evaluation of historic patterns of change along with continuous, long-term monitoring programs.

MethodMethod

Define a problem to be investigatedGet familiar and describe the study area by

visiting Narragansett Bay Commission website http://www.narrabay.com/

Hypothesis what processes may affect nitrate concentrations and transport in Narragansett Bay

Locate the six monitoring stations in Narragansett Bay on the map by visiting the website of National Estuarine Research Reserve System’s Centralized Data Management Office http://cdmo.baruch.sc.edu/QueryPages/viewstations.cfm?Site_ID=nar

Method (Cont’d)Method (Cont’d)Get familiar with the archived and near-

real time water and nutrient data from the different stations

Plot nitrate, water depth, salinity and temperature measured at one of the stations during 2006 for the following dates: January 9-14, March 9-14, June 9-14 and September 9-14.

Examine the graphs and see if there is any rhythmic or consistent pattern. Pay attention to the differences in the trends observed between the different months.

Data Summary: A SampleData Summary: A Sample

Data SummaryData Summary

Temperature and nitrate charts display Temperature and nitrate charts display reverse trends.reverse trends.

Salinity and Nitrate charts display Salinity and Nitrate charts display somewhat similar trends.somewhat similar trends.

No clear relationship is shown between No clear relationship is shown between the depth and nitrate concentration.the depth and nitrate concentration.

ConclusionConclusion

Certain relationships could be Certain relationships could be found between nitrate found between nitrate concentrations and some water concentrations and some water data in Narragansett Bay.data in Narragansett Bay.

ImplicationsImplications

Based on the findings, predict and draw a map of how nitrate enters and circulates through the Narragansett Bay.

Use the data set available in the website of National Estuarine Research Reserve System’s to support or refute your predictions. Redraw the map according to your findings.

Educator ImplicationsEducator Implications

Walk students through the data cleaning Walk students through the data cleaning process. Different data sets might have process. Different data sets might have different formats, time ranges, etc.different formats, time ranges, etc.