coliform sample siting plan ken morin, p.e. blm national applied resource sciences center

Coliform Sample Siting PlanColiform Sample Siting Plan

Ken Morin, P.E.Ken Morin, P.E.

BLMBLM

National Applied Resource National Applied Resource Sciences CenterSciences Center

Coliform SamplingColiform Sampling40 CFR 141.21(a)(1)40 CFR 141.21(a)(1)

• Routine monitoringRoutine monitoring. Public water . Public water systems must collect total coliform systems must collect total coliform samples at sites which are samples at sites which are representative of the water throughout representative of the water throughout the distribution system according to a the distribution system according to a written sample siting plan.written sample siting plan.

• These plans are subject to State These plans are subject to State review and revision.review and revision.

Coliform Sample Siting Plan Coliform Sample Siting Plan

• Plan elements are not defined in Plan elements are not defined in the regulations.the regulations.

• Very brief guidance is available Very brief guidance is available from some States.from some States.

• New BLM Drinking Water Manual New BLM Drinking Water Manual will provided detailed will provided detailed requirements.requirements.

Recommended Elements Recommended Elements in Sample Siting Planin Sample Siting Plan

• Map showing the following:Map showing the following:

– Distribution systemDistribution system

– StorageStorage

– TreatmentTreatment

– TapsTaps

– Identification name/number for Identification name/number for each tapeach tap

Recommended Elements in Recommended Elements in Sample Siting Plan Sample Siting Plan [continued][continued]

• Break Distribution System into Break Distribution System into Zones if it is Looped or has Zones if it is Looped or has Different Pressure Zones.Different Pressure Zones.

• Alternate Samples Between Zones Alternate Samples Between Zones

• Focus Samples At:Focus Samples At:

– Dead endsDead ends

– Heaviest use tapsHeaviest use taps


• Routine Sample ScheduleRoutine Sample Schedule

– Sample to be taken early in Sample to be taken early in month/quartermonth/quarter

– Quarter defined as Jan. - March, etc.Quarter defined as Jan. - March, etc.

• Sampling ProceduresSampling Procedures

• How to Fill Out Lab FormHow to Fill Out Lab Form


• Description of Sampling that Must Description of Sampling that Must be Done if a Routine Sample Tests be Done if a Routine Sample Tests Positive Positive [141.21(b)(2)][141.21(b)(2)]

• Do Not Disinfect Following a Positive Do Not Disinfect Following a Positive Routine SampleRoutine Sample

• Actions to be Taken if a Repeat Actions to be Taken if a Repeat Sample Tests Positive Sample Tests Positive [ 141.21(b)(4)][ 141.21(b)(4)]


• ““Increased” Routine Samples Must Increased” Routine Samples Must be Taken Regardless of Whether Any be Taken Regardless of Whether Any Repeat Sample Tests Positive Repeat Sample Tests Positive [141.21(b)(5)][141.21(b)(5)]

• Public Notification Requirements Public Notification Requirements [141.21(g) and 141.32][141.21(g) and 141.32]– Two positives in one month exceeds MCL Two positives in one month exceeds MCL

[141.63(a)(2)][141.63(a)(2)]– Failure to monitor for coliforms [141.21(g)(2)]Failure to monitor for coliforms [141.21(g)(2)]


• Disinfection Procedures for:Disinfection Procedures for:

– WellWell

– Storage tankStorage tank

– Distribution systemDistribution system


• Water System Startup ProceduresWater System Startup Procedures

– Opening and closing which valvesOpening and closing which valves

– Disinfection procedures for storage and Disinfection procedures for storage and distributiondistribution

– Satisfactory coliform result prior to Satisfactory coliform result prior to openingopening

• Operational Testing FrequencyOperational Testing Frequency


• Water System Shutdown Water System Shutdown ProceduresProcedures

– Opening and closing which valvesOpening and closing which valves

– Draining distribution and storageDraining distribution and storage

– Equipment to be brought back Equipment to be brought back from the fieldfrom the field

Recommended Elements in Recommended Elements in Sample Siting Plan Sample Siting Plan [concluded][concluded]

• Recordkeeping RequirementsRecordkeeping Requirements

• State Reporting Requirements for:State Reporting Requirements for:

– Positive repeat coliform resultPositive repeat coliform result

– Public notification postingsPublic notification postings

– Operational testing resultsOperational testing results

• State Certification RequirementsState Certification Requirements

Sampling Following a Sampling Following a Positive - 1 TapPositive - 1 Tap

• One Repeat Sample One Repeat Sample [141.21(b)(3)][141.21(b)(3)]

– Four 100 mL samples:Four 100 mL samples:–first taken early in morningfirst taken early in morning–second taken 2 or 3 hours latersecond taken 2 or 3 hours later–third taken 2 or 3 hours after secondthird taken 2 or 3 hours after second– fourth taken 2 or 3 hours after thirdfourth taken 2 or 3 hours after third

– Refrigerate or ice samples awaiting Refrigerate or ice samples awaiting shipment to labshipment to lab

Sampling Following a Sampling Following a Positive - 1 Tap Positive - 1 Tap [concluded][concluded]

• Five “Increased” Routine Samples Five “Increased” Routine Samples [141.21(b)(5)][141.21(b)(5)]

– Routine samples must be taken in month Routine samples must be taken in month following the positive [following the positive [40 CFR 40 CFR 141.21(b)(5)]141.21(b)(5)]

– Routine samples must be taken at regular Routine samples must be taken at regular time intervals throughout the month time intervals throughout the month [141.21(a)(4)][141.21(a)(4)]

– Therefore a sample must be taken every 5 Therefore a sample must be taken every 5 or 6 daysor 6 days

Sampling Following a Sampling Following a Positive - 2 TapsPositive - 2 Taps

• Four Repeat Samples Four Repeat Samples [141.21(b)(2)][141.21(b)(2)]

– One sample from each tap taken One sample from each tap taken early in morningearly in morning

– One sample from each tap taken One sample from each tap taken as late as possible the same dayas late as possible the same day

– Repeat samples must be taken on Repeat samples must be taken on the same day the same day [141.21(b)(3)][141.21(b)(3)]

Sampling Following a Sampling Following a Positive - 2 TapsPositive - 2 Taps [concluded][concluded]


– Routine samples must be taken at regular Routine samples must be taken at regular time intervals throughout the month time intervals throughout the month [141.21(a)(4)][141.21(a)(4)]–one sample from each tap at the one sample from each tap at the beginning of the monthbeginning of the month

–one sample from each tap at the middleone sample from each tap at the middle–one sample from original positive tap at one sample from original positive tap at the end of the monththe end of the month



– One sample from each tap taken early One sample from each tap taken early in morningin morning

– One sample from the original positive One sample from the original positive tap taken as late as possible the same tap taken as late as possible the same dayday

– Repeat samples must be taken on the Repeat samples must be taken on the same day same day [141.21(b)(3)][141.21(b)(3)]

Sampling Following a Sampling Following a Positive - 3 TapsPositive - 3 Taps [concluded][concluded]


– Routine samples must be taken at regular Routine samples must be taken at regular time intervals throughout the month time intervals throughout the month [141.21(a)(4)][141.21(a)(4)] –One sample from each tap at the One sample from each tap at the beginning of the monthbeginning of the month

–One sample from original positive tap One sample from original positive tap and any other tap at the middle of the and any other tap at the middle of the monthmonth



– One sample from each tap One sample from each tap

– Repeat samples must be taken on Repeat samples must be taken on the same day the same day [141.21(b)(3)][141.21(b)(3)]

– Samples are to be taken within 24 Samples are to be taken within 24 hours of notification of positive hours of notification of positive [141.21(b)(1)][141.21(b)(1)]

Sampling Following a Positive Sampling Following a Positive - 4 Taps - 4 Taps [concluded][concluded]


– Routine samples must be taken at Routine samples must be taken at regular time intervals throughout the regular time intervals throughout the month month [141.21(a)(4)][141.21(a)(4)]

–One sample from each tap at the One sample from each tap at the beginning of the monthbeginning of the month

–One sample from original positive tap One sample from original positive tap at the middle of the monthat the middle of the month

Sampling Following a Positive Sampling Following a Positive - 5 to 7 Taps- 5 to 7 Taps


– One sample from original positive tap One sample from original positive tap – Other samples from any three different Other samples from any three different

tapstaps– Repeat samples must be taken on the Repeat samples must be taken on the

same day same day [141.21(b)(3)][141.21(b)(3)]

– Samples are to be taken within 24 hours Samples are to be taken within 24 hours of notification of positive of notification of positive [141.21(b)(1)][141.21(b)(1)]

Sampling Following a Positive Sampling Following a Positive - 5 to 7 Taps- 5 to 7 Taps [concl’d][concl’d]


– Systems that serve < 4,900 persons may Systems that serve < 4,900 persons may collect all required samples on a single collect all required samples on a single day if they are taken from different taps day if they are taken from different taps [141.21(a)(4)][141.21(a)(4)]

–One sample from original positive tap at One sample from original positive tap at the beginning of the month the beginning of the month

–Four other samples any four different Four other samples any four different tapstaps

Sampling Following a Positive Sampling Following a Positive 8 or More Taps8 or More Taps

• Four Repeat Samples to be Taken Four Repeat Samples to be Taken per 141.21(b)(2)per 141.21(b)(2)

• Five “Increased” Routine Samples Five “Increased” Routine Samples Taken From 5 Different Taps on Taken From 5 Different Taps on the Same Day the Same Day [141.21(b)(5) & (a)(4)][141.21(b)(5) & (a)(4)]

– One of the samples should be taken One of the samples should be taken at the original positive tapat the original positive tap

Repeat Sample CollectionRepeat Sample Collection

• Four Repeat Samples Must be Taken Four Repeat Samples Must be Taken [141.21(b)(1)][141.21(b)(1)]

• Samples to be Taken Within 24 Hours Samples to be Taken Within 24 Hours of Positive Result Notification of Positive Result Notification [141.21(b)(1)][141.21(b)(1)]

• Repeat Sample Locations Repeat Sample Locations [141.21(b)(2)][141.21(b)(2)]

• All Repeats to be Taken on Same Day All Repeats to be Taken on Same Day [141.21(b)(3)][141.21(b)(3)]


• If Any Repeat Tests Positive Another If Any Repeat Tests Positive Another Set of Repeats Must be Taken; Set of Repeats Must be Taken; [141.21(b)(4)][141.21(b)(4)] or or

• Notify the State that the Coliform Notify the State that the Coliform MCL has been Violated per 141.63 MCL has been Violated per 141.63 [141.21(b)(4)][141.21(b)(4)]

• State May Still Require Additional State May Still Require Additional SamplingSampling


• System with One Tap May System with One Tap May Collect One Repeat Sample Each Collect One Repeat Sample Each Day for Four Days; orDay for Four Days; or

• Collect a Single 400 mL Sample Collect a Single 400 mL Sample [141.21(b)(3)][141.21(b)(3)]

– This should be a composite sampleThis should be a composite sample

““Increased” Routine Sample Increased” Routine Sample CollectionCollection• Five “Increased” Routine Samples Must be Five “Increased” Routine Samples Must be

Taken in the Month Following a Positive Taken in the Month Following a Positive SampleSample [141.21(b)(5)][141.21(b)(5)]

• Collect Samples at Regular Time Intervals Collect Samples at Regular Time Intervals Throughout the MonthThroughout the Month [141.21(a)(4)][141.21(a)(4)]

• Except Systems that Serve < 4,900 PersonsExcept Systems that Serve < 4,900 Persons– May collect all required samples on a single May collect all required samples on a single

day if they are taken from different taps day if they are taken from different taps [141.21(a)(4)][141.21(a)(4)]

coliform sample siting plan ken morin, p.e. blm national applied resource sciences center

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