Department of the Environment

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

PWS Requirements Required By:

Notification of 4-log treatment of viruses December 1, 2009

Required Beginning:

Triggered source water monitoring

December 1, 2009

Corrective actions

Compliance monitoring

New sources placed in service must meet triggered source water monitoring requirements or conduct compliance monitoring for 4-log treatment of water

States can require GWSs to conduct assessment source water monitoring

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

1. Sanitary surveys. (MDE)

2. Corrective action. (MDE- Water Systems)1. Significant deficiencies.

2. Fecal contamination.

3. Monitoring. (You- Water Systems)1. Source Water Monitoring. (Triggered or Assessment)

2. Compliance Monitoring.

Ground Water System

Triggered SourceWater Monitoring

4 Log Treatment and Compliance MonitoringAssessment 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

1. E. coli

2. Enterococci

3. Coliphage

Fecal Indicator Methodology Method Name

E. coli Colilert

Colisure

Membrane Filter Method with MI Agar

m-ColiBlue24 Test

E*Colite Test

EC-MUG

NA-MUG

9223 B

9223 B

EPA Method 1604

9221 F

9222 G

Enterococci Multiple Tube Technique

Membrane Filter Technique

Membrane Filter Technique

Enterolert

9230 B

9230 C

EPA Method 1600

Coliphage Two-step Enrichment Presence-Absence Procedure

Single Agar Layer Procedure

EPA Method 1601

EPA Method 1602

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

3

2

1

System B Consecutiv

e

WholesaleSystem

TC+

EC+W1 W2

System A Consecutiv

e

System A notifies wholesale GWS of TC-positive sample collected under the TCR.

Wholesale GWS samples ground water sources for fecal indicator.

Wholesale GWS notified of source water fecal indicator-positive result notifies all consecutive GWSs served by source, and undertakes state-approved corrective action(s).

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)

low pressure zone

Well 1Well 3

TCX

TCY

TCZ

Well 1 Well 3Well 2

Low Pressure Zone

Mixed Zone

High Pressure Zone

1800 Washington Boulevard | Baltimore, MD 21230-1718410-537-3000 | TTY Users: 1-800-735-2258

www.mde.state.md.us

Maryland Department of the Environment

Travis E. Sterner, R.S.Water Supply Program

Interior Pages

• Type.

• Here.