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Ground Water Rule. Laboratory Presentation. Presentation Overview. Why the GWR regulations were created. General requirements of the GWR. Focus on laboratory/ sampling requirements. Handouts/ question and answer. Why??.
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Ground Water Rule Laboratory Presentation
Presentation Overview • Why the GWR regulations were created. • General requirements of the GWR. • Focus on laboratory/ sampling requirements. • Handouts/ question and answer.
Why?? • EPA is particularly concerned about ground water systems (GWSs) that are susceptible to fecal contamination because these systems may be at risk of supplying water that contains harmful microbial pathogens
Purpose of the GWR • Reduce public health risk associated with fecal contamination for people served by groundwater sources. • Viruses • Bacteria
To Whom Does the GWR Apply • Systems producing and relying 100% on ground water. • Consecutive systems receiving ground water. • Mixed systems using surface and ground water. • Unless they combine all their ground water with surface water prior to treatment meeting the SWTR.
Key Provisions of the GWR • Sanitary surveys. (MDE) • Corrective action. (MDE- Water Systems) • Significant deficiencies. • Fecal contamination. • Monitoring. (You- Water Systems) • Source Water Monitoring. (Triggered or Assessment) • Compliance Monitoring.
Ground Water System 4 Log Treatment and Compliance Monitoring Triggered Source Water Monitoring Assessment Source Water Monitoring
GWR and TCR Relationship • TCR and the GWR work together. • TCR positive may indicate a problem with the ground water source. • So, a TCR positive sample triggers a “Triggered Source Water Sample” • Exceptions
Triggered Source Water Sample • Ground water system must. • Collect at least 1 raw water sample per TCR positive at each source that was operating when the TCR positive sample was taken. • Collect the triggered source water sample within 24 hours of being notified of the positive TCR sample. • Time extension is possible.
Triggered Source Water Sample • Must be analyzed for a fecal indicator • E. coli • Enterococci • Coliphage
Sampling Location • Sample at well or state-approved location • Sample before treatment • Might be necessary for GWS to install new sample tap • GWSs with multiple sources may request approval from state to reduce number of locations
Systems Serving ≤ 1,000 people • Ground water systems may use a TCR repeat sample to satisfy the GWR triggered source water sample. • Lab must use an approved E. coli method
What if the “Initial Triggered Source Water” is Positive • GWS must take 5 “Repeat Triggered Source Water Samples” within 24 hours of being notified of the positive “Initial Triggered Source Water Sample.” • Unless state has already required corrective action. • See GWR Monitoring Report Form
What if any of the “Repeat Triggered Source Water Samples” are Positive • The Ground Water System must take corrective action.
Consecutive & Wholesale Systems • Consecutive Systems • Notify wholesale system(s) of total coliform-positive routine sample taken under the TCR • Notification required within 24 hours • Notification must be provided to all wholesale system(s) with ground water source(s) that had provided water to the consecutive system • Wholesale Systems • Upon receipt of notification from consecutive system: • Collect samples from all ground water sources serving the consecutive system within 24 hours of notice • For any fecal indicator-positive sample, notify all consecutive systems served by that ground water source within 24 hours
System A Consecutive TC+ System B Consecutive W1 W2 1 System A notifies wholesale GWS of TC-positive sample collected under the TCR. Wholesale GWS notified of source water fecal indicator-positive result notifies all consecutive GWSs served by source, and undertakes state-approved corrective action(s). 3 Wholesale System Wholesale GWS samples ground water sources for fecal indicator. 2 EC+
Representative Monitoring • States may allow for GWSs with multiple sources • Allows system to collect triggered source water sample(s) that represent each monitoring site in TCR sample siting plan • Representative sample locations must be approved by state
Triggered Source Water Monitoring Plan • For multi-source systems: • Identify ground water sources that are representative of each TCR monitoring site • Each TCR site needs to be associated with at least one source • May need to submit the plan to the state for approval (if directed by the state)
TCY High Pressure Zone TCX TCZ Mixed Zone low pressure zone Low Pressure Zone Well 1 Well 3 Well 2 Well 3 Well 1
1800 Washington Boulevard | Baltimore, MD 21230-1718410-537-3000 | TTY Users: 1-800-735-2258www.mde.state.md.us Maryland Department of the Environment Travis E. Sterner, R.S.Water Supply Program
Interior Pages • Type. • Here.