resolving drinking water non-compliance mcl violations

Resolving Drinking Water Non-compliance

MCL Violations

KY Public Water System Violation Trends

2

2007 2008 2009 2010 2011 20120

100

200

300

400

500

600

700

800

900

1000

74113 99

130103

47

913

639 648

459 451

791

Public Water System Violation Trends 2007-2011

Health-based

M&R

2012: Chlorine, TOC, Coliforms, CCR, MOR

KY Public Water System Violation Trends

2007

2008

2009

2010

2011

2012

State

Borde

r Sta

tes

Kentu

cky

Tenne

ssee

Wes

t Virg

inia

Miss

ouri

Virgini

a

India

naOhio

Illino

is

EPA R4

State

s

Kentu

cky

Alabam

a

Tenne

ssee

Miss

issipp

i

South

Car

olina

Georg

ia

Florida

North

Car

olina

0

100

200

300

400

500

600

700

800

2007-2012 Violation History by Violation Category

MCL

TT

RPT

MON

PN

SS

Total Coliforms/E. coli

Total Coliform

• Positive total coliform/E.coli is almost always associated with problems with– Sample site– Sampling technique

Total Coliform—Sample Site• Sample Site (or “Hey I had a good chlorine

residual at that site!!)– No outdoor faucets!!

• The #1 reason for positives

– No swing faucets– No dirty faucets– No hydrants

• No need to disinfect and most definitely don’t “flame” a faucet

• Good site and sample locations will reduce and even eliminate positive samples

Total Coliform—Sampling

• All samplers shall be trained in the proper sampling technique– No old bottles or bottles that have been rolling

around in the bed or floorboard of a vehicle– No setting tops down or in pockets or held in the

mouth– If removing strainers, do so carefully– Keep samples at 4 degrees C in a dedicated

cooler

RTCR Assessment Impact

In wine there is wisdom, in beer there is strength, in water there is bacteria (David Auerbach 2002)

Year Level 1 Level 2 Comment on Level 2

2008 17 3 All CWS (2 SW, 2 SWP)

2009 17 3 1 CWS, 1 TNC

2010 22 3 2 CWS (1 SW, 1 SWP), 1 TNC

2011 19 1 CWS (1 SWP)

2012 16 0

Disinfection By-Products

DBPs—At the Source

• Start at the source–Pay attention to the source water total

organic carbon (TOC) loading• Actual TOC data or UV254• Is it related to algal blooms or rainfall or

agricultural activity?• Treat the source if needed

– Be careful using copper sulfate for algal control as it will break up the algae, causing T&O, turbidity and possibly release microtoxins

DBPs and Plant Design

• It starts with good engineering– Design for the source water needs, not the

“technology of the day”• Or the technology should resolve the problem

– There should be flexibility in chemical feed points and what chemicals can be applied • This is a case of more is better

– Too much design flow capacity (i.e., plant not operating) can create problems in the plant• No flow through means more time for the chlorine to

react in sedimentation basins and clearwells

DBPs and Coagulation• Then move to the treatment process, starting

with coagulation– Optimize coagulation

• You may find that the coagulation dosage needed for organics removal is different than that for turbidity removal—this is called “simultaneous compliance”

– Try feeding PAC• Although the dosages may be very high• Avoid the pre-chlorine feed site

– Look at Step 2 jars or permanent alternative TOC compliance• Particularly if your system has TOC violations but not

ones for DBPs

DBPs and Disinfection

• Once done with the coagulation process, examine plant disinfection practices– Minimize the amount of pre-chlorine added

• If chlorine usage is for oxidation as well as disinfection, evaluate other oxidants (KMnO4, H2O2)

– Move the point of pre-chlorine addition to top-of-filter• PWSs must request to move the point of chlorination

– Watch the chlorine levels leaving the plant• More is not always better

DBPs and Disinfection

• For disinfection, what if the plant needs to move the point of chlorination but can’t because of the “1 log” C-T inactivation requirement??– 2013 is a different drinking water world than 1998– On a case-by-case basis, the DOW may

reconsider the 1-log C-T inactivation but cannot lower it below 0.5-log

– Back to “simultaneous compliance”• Decreasing DBPs while avoiding TCR problems

DBPs and Distribution Systems

• And finally the distribution system– DOW data shows that the majority of the PWSs

are forming the DBPs in the distribution system• Plant tap levels are low

– Good communication between plant, distribution and management personnel is critical• No more “finger-pointing”

DBPs and Distribution Systems• Again, it involves good engineering

– As the operator(s)—BE INVOLVED!– The engineered project should not compound or

create DBP problems• More tanks, booster stations, long lines with minimal

usage—not good• More water movement, more tank mixing--good

– Does your system have a hydraulic model and does it consider water quality impacts?• In other words, water age

DBPs versus Booster Chlorination• This is a real dilemma

– Low chlorine in an area with maybe the occasional positive TCR sample (maybe you ought to figure out why…)

– Flushing doesn’t seem to help and is expensive– Booster chlorination is considered

• Carefully examine where the booster station is placed (back to engineering and hydraulics)– If with a tank, after the tank is preferred– Automatic, SCADA control is preferred with an on-line

chlorine analyzer– Seasonal booster chlorination is always when DBP formation

is the highest

DBPs versus Water Age

• Water Age–The older the water, the more likely DBPs

will be formed

Chlorine + organics + time = DBPs

DBPs versus Storage Tanks

• Storage tanks– How many tanks are really needed? (and do

regulations need to be reviewed to reflect the 2013 world?)

– Too many tanks are being used for pressure and so the water in them cannot be adequately turned over

– Is there a better way to avoid the tank-to-tank-to-tank movement of water?

– Can you do more than monitor the water levels in the tanks—can you control it??

Multiple tanks in an area

Multiple tanks & booster stations—Driven by terrain

DBPs versus Water Mains• Water Mains

– In an effort to provide water to all KY residents by 2020, KY drinking water infrastructure is now available to 93-95% of Kentuckians

– Residential water usage is dropping• Now estimated at 65 gallons per person per day• Number of people in a residence is dropping

– In 1990s it was 3.3, in 2006 it was 2.97 and in 2010 is was 2.49

– May have long mains with little usage – Or big mains to potential high usage areas that

never developed

DBPs versus Flushing

• Flushing should be for more than “spot compliance”– KY regulations only recommend – But good distribution operation dictates that it

should be routine practice– Scheduled, unilateral, from the plant out, water

quality-based– Not just before compliance monitoring– Consider automatic flushers in areas that require

more frequent turnover • And what are you basing that on??

In Closing…..

DBP Formation and Compliance

• Chlorine is a good thing in water treatment– No acute, microbial-based public health concerns– So we can’t just stop chlorinating

• Other disinfectants also have by-product issues– Chlorine dioxide, chloramines, ozone

• Today’s source water is not getting any cleaner– And systems don’t always have another source

water option

DBP Formation and Compliance

• Today’s operators are challenged with “simultaneous compliance”– How to stay in compliance with regulations that

may not work together– Then there is the Clean Water Act impacts on

source water and maybe how we treat water (a whole other story)• Remember

“We are all downstream”(Ecologist’s Motto)

DBP Formation and Compliance

• We all have to work smarter not harder because we are all in this together: plant operators, distribution operators, management, engineers, regulators– Gather the data and look at it and stay ahead of

the problems• Once you get the NOV, it may be too late

– What are the best overall option(s) for protecting public health—not just the cheapest or the newest technology, engineering or operations• There may need to be multiple options

– Communicate– Keep trying

Comments?? Questions??

KY Drinking Water Program• Program Coordinator

• Compliance• Technical Assistance

• Inspectors• Capacity Development

• Engineering