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The Ground Water Rule and You. Advanced Small Water System Course 2013. GWR – Presentation Outline. Its Purpose Key provisions (required sampling, terminology, compliance actions, etc.) Results of Source Monitoring to Date Tools for Water Systems
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The Ground Water Rule and You Advanced Small Water System Course 2013
GWR – Presentation Outline • Its Purpose • Key provisions (required sampling, terminology, compliance actions, etc.) • Results of Source Monitoring to Date • Tools for Water Systems • Class Exercise: Coliform Sampling Plan, Lab Slip Terms
The whole point of the Groundwater Rule (GWR): To protect us from fecal contamination (either bacteria or viruses) in the source water.
The whole point of the Groundwater Rule (GWR): If it’s not in the source water... GWR does not apply If it’s not fecal… GWR does not kick in
Significant Deficiencies New, with the GWR: DWP has explicit authority to see that GW systems correct significant deficiencies/rule violations; Establishes a timeline for correcting these deficiencies identified during a water system survey.
Timeline – Systems Must: Significant Deficiencies Consult with their regulator (County or State DWP) within 30 days of written notice, to explain how the system plans to correct the deficiencies ; and Complete the action (or be on an approved schedule to complete it) within 120 days.
Significant Deficiencies -Timeline July September October August Survey conducted 30-day Consultation Deadline November Survey/ Notice of deficiency received 120-day Correction Deadline
Significant Deficiencies Failure to comply with the correction requirement will result in: A Violation, and A Tier 2 (30-day) Public Notice
Are Fecal Microbes in Your Source Water? How would you know if you only sample water that has already been disinfected? Must adjust the sampling approach based on whether or not your system has disinfection treatment
Are Fecal Microbes in Your Source Water? Of the 3,155 groundwater systems in Oregon: No disinfection treatment (66%) Either UV or unverified chlorine disinfection treatment (33%) Treatment with ongoing Compliance Monitoring (1%) – will describe later
So which boat are you in? Oregon GW systems
The GW Rule is intended to protect us from fecal contamination (bacteria and viruses) in the source water. How does that play out in each of these situations?
Boat 1: No Disinfection Treatment If there’s fecal contamination at the source, E. coli will show up in routine distribution testing
Boat 1: No Treatment –When does GWR say to sample at the source? • Since the routine samples already show the microbial content of the source water… • Only impact of the GWR: After a positive routine, take 1 sample from each active source (& mark it as “source”). We’ll hear more about this “triggered sampling” in a bit…
Boat 3: Compliance Monitoring = 4-log Virus Inactivation (99.99%) + Daily Monitoring of Chlorine Residual 4-log viral inactivation
Boat 3: Compliance Monitoring - When does GWR say to sample at the source? No, not really Does it make sense to keep taking raw source samples if their treatment is confirmed to inactivate fecal microbes, and they monitor it every day?
Leaving us with Boat 2 - Boat 2 = Systems with disinfection treatment, but not verified for 4‑log inactivation of viruses (33% of OR groundwater systems) Is this you? How does the GWR apply to this “in between” situation?
Boat 2: Treatment that is not verified as 4-log for viruses- Viruses (e.g., adenoviruses) are more likely to survive standard UV treatment than bacteria. Hmm – no fecal bacteria/E. coli there, but… look at those “v”s! v v v
If tap water samples show no fecal bacteria (E. coli) - Factoid: “Norwalk and Norwalk-like viruses are recognized as the major causes of waterborne illnesses world-wide.” Symptoms: watery diarrhea and vomiting v v v How can we tell if a fecal virus might remain in the drinking water?
Test water for viruses? $$$ Not so easy. It’s hard to take valid virus samples, and they are expensive lab tests
Let’s be practical - Can we narrow down the likelihood of fecal viruses in a given source? Well, “fecal contamination” would include fecal bacteria as well as viruses, so…
Voila! We can test for fecal bacteria at the source! We can use a standard test for fecal bacteria (E. coli) as an indicator for ANY fecal contamination. Bonus feature - Everyone is used to taking coliform samples for the lab already, and they are fairly inexpensive.
If the source sample is negative for fecal bacteria (E. coli)… Possible Source Water Test Results: E. coli negative E. coli negative E. coli positive v b v b v b v v v v But still fecal viruses present? - Not likely Means fecal contamination No fecal contamination Chances are good there is no fecal contamination in the source water, and no fecal viruses to worry about.
So, source water coliform tests will tell if there are fecal contamination risks
Back to how the GWRapplies to Boat 2 • What sampling is required? In this situation, the GWR gives both: • A regular time interval; plus • A circumstance that triggers sampling at the source for the fecal indicator (E. coli). Boat 2 = systems with treatment but not verified for 4‑log inactivation of viruses
GWR – Presentation Outline • Its Purpose • Key provisions: • Water System Surveys & Significant Deficiencies • Finding Fecal Bacteria & Viruses in Source Water • Source Water Monitoring – Terminology • If Fecal Contamination in Source - Public Notice & Corrective Action
Types of Source Water Monitoring under the GWR • Assessment Source Monitoring • Triggered SourceMonitoring • Additional (or “Confirmation” )Source Monitoring Wellhead with sample tap
1. Assessment Source Monitoring “Assessment Monitoring” is sampling on a regular schedule, not tied to another test’s result. There are two types under GWR: • Annual sampling - Every GW system* that disinfects must submit at least 1 source sample per year *Unless conducting Compliance Monitoring
1. Assessment Source Monitoring • Monthly Monitoring: • Only applies if notified by the Dept • Is short-term (ends after a year) • Is aimed at sources susceptible to fecal contamination • Higher risk sources identified based on both hydrogeologic sensitivity and proximity of contaminants
Identifying Systems for Monthly Assessment Source Monitoring Data sources: • Source Water Assessment Reports; • Monitoring history; • Staff knowledge of GW source
Monthly AssessmentSource Water Monitoring The Source Water Assessment reports identify: • Inadequate source construction • Highly sensitive aquifer characteristics, and • Fecal contaminant sources within the 2-year Time-of-Travel Zone time of travel to well
Inadequately Constructed Well Susceptible to Fecal Contamination
2. Triggered Source Monitoring GW systems* must collect triggered source samples when: • A routine coliform distribu-tionsample is positive (that’s the “trigger”). *Unless conducting Compliance Monitoring
2. Triggered Source Monitoring Basically, the GWR uses the presence of bacteria in the distribution system as another time to check the microbial content of the source water ?
Special Case of Triggered Monitoring- Purchasing & Wholesale Systems • Purchasing Systems: • Must notify wholesale system of a TC+ distribution sample. • Wholesale Systems (when notified): • Must collect samples from all GW sources serving the system • If any source sample is fecal positive, must notify consecutive systems served by that GW source
3. Additional/”Confirmation”Source Water Monitoring If a source sample is E. coli +, the system must confirm findings by: • Taking 5 “confirmation” source samples… • within 24-hours of being notified about the E. coli+ sample, and • from the same source(s) that had an E. coli+ result
3. Additional/Confirmation Source Water Monitoring • If any of the 5 confirmation source samples are fecal positive, system must take corrective action.
Scenario Exercise – What actions would be required if?Which example matches your situation? • There’s no disinfection, and a distribution sample is positive? • 4 repeats, same as always (1 is at well) • There’s UV or chlorine disinfection, and… • A distribution sample is positive? • 4 repeats from distribution + source sample(s) • An assessment source sample is positive for total coliform? • If not fecal, it’s not a GWR concern
GWR – Presentation Outline • Its Purpose • Key provisions: • Water System Surveys & Significant Deficiencies • Finding Fecal Bacteria & Viruses in Source Water • Source Water Monitoring – Terminology and Who Does What • If Fecal Contamination in Source - Public Notice & Corrective Action
The Next Day…. Your sample has tested positive for E. coli ! Meep!
Friday Afternoon…. Your samples have tested positive for E. coli ! Meep! Meep! Meep! Meep! Meep!
Call your Regulator!(Or maybe they will call you) • Focus is on protecting Public Health from fecal content in the source water. • Together, evaluate existing disinfection treatment (if any), leading to a decision on: • Whether a Boil Water Notice is required; • What interim operating conditions may be imposed.
Public Notice • If your system does not chlorinate or have UV, the need for an immediate Tier 1 Boil Notice is clear. • If disinfected to 4-log virus inactivation, an immediate non-boil notice may suffice.