# Presentation: 601675

## EPA Review of TCR and Distribution System Issues

**Kenneth H. Rotert**
**US EPA Office of Ground Water and Drinking Water**
**ASDWA Annual Conference**
**October 25, 2001**

## Overview

**Background**
**Public Health Concerns**
**Activities to Date: TCR**
**Activities to Date: Distribution System Issues**
**Upcoming Activities**

## Background

**TCR Review and Revisions Required in SDWA**
**“****not less often than every 6 years, review and revise, as appropriate, each NPDWR...”**
**TCR Promulgated in 1989**
**M/DBP FACA Agreement (Sept. 2000)**
**Evaluate Available Data and Research on Aspects of Distribution Systems that may Create Risks to Public Health**
**Work with Stakeholders to:**
**Initiate a process for addressing cross connection control and backflow prevention requirements**
**Consider additional distribution system requirements related to significant health risks**

## Public Health Concerns

**Outbreaks Related to Distribution Systems**
**66 Distribution System Outbreaks Between 1981-1998**
- 64% of distribution system outbreaks (42) in CWSs
- 21% of distribution system outbreaks (14) in NCWSs
**18% of Outbreaks 1981-1998**
**Contaminants in Distribution System Outbreaks (CDC Data)**
**Chemical Outbreaks with 100 or More Ill or at Least One Death**
- Copper - 9 outbreaks/125 ill
- Ethylene Glycol - 2 outbreaks/30 ill/1 death
**Microbial Outbreaks with 100 or More Ill or at Least One Death**
*Campylobacter* species - 4 outbreaks/513 ill
- Norwalk virus - 2 outbreaks/225 ill
*Salmonella* species - 4 outbreaks/1496 ill
*Giardia* species - 10 outbreaks/2034 ill
- AGI - 16 outbreaks/1975 ill
*Shigella* species - 4 outbreaks/118 ill
*E. coli* - 1 outbreak/243 ill/4 deaths
- SRSV - 1 outbreak/148 ill

## Activities to Date: TCR Review

**Notice of Intent - Six-Year Review**
**NOI Being Published Along with Six-Year Review of Chemical Contaminants **
**Regulatory Review and Development Being Carried Out on Separate Track **
**Comments Received on TCR**
**Unsolicited Comments Reviewed**
- Received since 1989 promulgation date** **
**Solicited Comments January, 2001**
- Comments solicited from EPA Regions, States, ASDWA, AWWA, AMWA, NRWA and ASM
**Total 66 Letters, 827 Comments**

## Activities to Date: TCR Review

**Routine Monitoring Comments**
**Increase Minimum to Greater than One Sample Per Year**
**Base Sampling Frequency on Risk (Cross connections, SWAP)**
**Waive TC Monitoring if Undisinfected, no Distribution System**
**Increase Requirements if MCL or Monitoring Violation**
**Use TC as an Initial Screen with *****E. coli***** Follow-Up**
**Statistically Determine Number of Monthly Samples Required**
**Review Monitoring Requirements through Stakeholder Process**
**Follow-up Monitoring Comments**
**Drop Fecal Coliforms, Keep *****E. coli***
**Drop Five Routine Samples Following Month**
**More Flexible Location for Fourth Repeat Sample**
**Clarify Repeats in Systems w/o Distribution System**
**Better Ways Exist to Determine Plumbing Problem**

## Activities to Date: TCR Review

**MCL Comments**
**Drop MCL for TC, Keep for *****E. coli***
**Change to Action Level**
**Site Sampling Plan Comments**
**Greater Flexibility - Emphasize Monitoring Critical/Vulnerable Sites**
**Allow for Dedicated Sampling Taps**
**Concern over Sampling Consumer Taps**
**Violation and Reporting Comments**
**Reduce Number of Monitoring and Reporting Violations**
**Streamline and Simplify Reporting**
**Definitions Comments**
**Re-examine Definitions for MCLs/MCLGs**
**Add/Refine Definitions - Violations, Compliance and PWS**

## Activities to Date: Distribution Systems

**Expert Panel Convened June 2000**
**Attendees - OGWDW, ORD, Academia, Utility Personnel, AWWSCo., Consultants, State Regulators**
**Discussed Health Risks Associated with Various Distribution System Issues**
**Agreed on the Preparation of White Papers on Issues Ranked of Significant Health Risk Concern**
**White Paper Purpose**
**Characterize Health Risks Associated with Distribution System Issues and Potential Solutions for Reducing the Risks**
**Use as an Informational Source for Regulatory Development**

## Activities to Date: Distribution System White Papers

**White Papers Status**
**First Drafts Prepared**
- Cross Connection Control - (EPA) - Being revised
- Biofilms/Regrowth - (EPA) - Finalizing first draft
**First Drafts Under Preparation**
- Intrusion - (AWWSCo)
- Aging Infrastructure - (AWWSCo)
- Covered Storage - (AWWA)
- Decay in Water Quality over Time - (AWWA)
- Corrosion, Permeation and Leaching - (AWWA)
- Contamination Following Repair/Replacement - (AWWA)
- Nitrification - (AWWA)
**Additional Issues?**

## Cross Connection Control

**Cross Connections Can Lead to Backflow of Chemical or Microbial Contaminants**** **
**Where Uncorrected, Cross Connections Can Result in Long-Term Exposures.**
- Estimated 90% of backflow events unreported
- 26 Cross connection related outbreaks from 1981-1998 reported to CDC
**EPA Draft Cross Connection White Paper (October, 1999)**
**448 Backflow Events 1970-1999**
**124 Events Reported Illness - Estimated 11,854 Cases and 13 Deaths**
**Common Contaminants**
- Blue/green water - 34 incidents
- Ethylene glycol/antifreeze - 18 incidents
- Chromium species - 18 incidents
- Chlordane - 11incidents
*Giardia* - 10 incidents
**Common Elements Being Examined**

## Biofilms/Regrowth

**Several Pathways Through Which Microbes can Enter Distribution System**
**Microbes can Become Entrained in Biofilm**
**Some Organisms can Grow or Recover in Biofilm**
**Some Measure of Protection from Disinfectants Provided**
**Pressure Changes or Erosion Can Release Contaminants**
**May Interfere with the Utility of Indicator Organisms**
**Many Control Methods or Approaches Exist**
**Some Pathogens of Concern in Biofilms**
***Legionella***
***Mycobacterium Avium***** Complex**
***Helicobacter***** (?)**

## Intrusion

**Contaminants Can Enter When Pressure Drops**
**Leak Sites Become a Portal for Contaminant Intrusion**
**Well-Run Systems Average 10-20% Leakage**
**Common Causes of Pressure Drops**
**Pump Operation**
**Flushing Operations**
**Opening/Closing Hydrants**
**Changes in Demand**
**Main Breaks**
**Valve Operation**
**Power Failures**
**Significance of Intrusion**
**AWWARF Pathogen Intrusion Study (Kirmeyer et al., 2001)**
- Most sites had significant pressure drops
- Water samples exterior to pipe - 42.8% fecal coliform, 12.5% enteric virus positive

## Aging Infrastructure

**The Aging of Distribution System Infrastructure**
**Average Pipe Age 21-91 Years**
**Oldest Sections 35-140 Years**
**Pipes Older than 20 Years: 42.53 - 69.57%**
**Current Replacement Rates 0.5% Annually**
**Shortened Economic Lives of Materials**
**Multiple Generations of Infrastructure to Wear Out at Nearly the Same Time**
**Life Varies Depending on the Materials**
**Effects of Aging Infrastructure**
**Leakage and main breaks**
- Intrusion
- Backflow
**Enhanced Biofilm Development**
**Enhanced Corrosion**
**Water Quality Decay**

## Covered Storage

**Contaminants May Be Associated with Sediments**
**Coliforms**
**Inorganics (e.g., Radium)**
**Humans or Animals can Enter and Contaminate**
**Some Drowning have been Documented**
**Trash Disposal**
**Storage Time is a Concern**
***Klebsiella***** (Fecal Coliform) is a Concern in Redwood Tanks**
**Outbreaks Caused Associated with Covered Storage Vessels**
***Salmonella typhimurium***** Outbreak in Gideon, Mo.**
- Over 400 cases of illness and seven deaths
- Caused by bird feces contaminating an elevated storage tank

## Decay in Water Quality over Time

**Problems Associated with Excess Residence Times**
**Formation of Disinfection and Corrosion Byproducts**
**Enhances Proliferation of Microbes**
**Loss of Disinfectant Residual**
**Can Accumulate Contaminants for Later Release**
- Inorganics
**Taste, Color and Odor Problems**
**Causes of Excess Residence Time**
**Improperly Sized Distribution Systems**
**Low Flow Areas (e.g., Dead Ends)**
**High Demand Storage**
**Lack of Valve Exercise**

## Corrosion/Permeation/Leaching

**Corrosion**
**Causes Include Water Chemistry, Electric Grounding and Microbially-Induced**
**Possible Solutions Include Use of Newer Pipe Materials and Corrosion Control**
**More Understanding Needed on the Effects of Changing Chemical Treatment**
**Permeation**
**Causes Include Plastic Pipes in Close Proximity to Gas Tanks (VOCs) and Runoff**
**Possible Solutions Include Pipe Placement and the Use of Compatible Pipe Materials**
**Leaching**
**Linings (Including Asphalts with High VOCs), Improperly Cured Pipe Materials**
**Current Research Exploring the Potential of Leaching of Endocrine Disruptors (Include Phthalates, Bisphenols, Alkyl Phenols, Alkyl Phenol Ethoxylates and Polyethoxylates)**

## Contamination Following Repair/Replacement

**Improper Repair or Replacement Procedures**
**Lack of Standardized Procedures**
**Need to Return to Service ASAP**
**Lack of Proper Flushing and Disinfection**
**Effects of Improper Repair and Replacement**
**Microbial and/or Chemical Contaminants Introduced**
**Problems Associated with Large Releases of Chlorine**
- Dermal allergies
- Accelerated corrosion
- Customer complaints
**Some Potential Solutions**
**Licensed Operators**
**Supervisor Oversight**
**Replacement Policy and/or Program**

## Nitrification

**May be a Chloramine Issue When Excess Ammonia Added**
**Added Ammonia May Act as a Nitrogen Source for Nitrifying Bacteria**
**Also an Issue Related to Naturally-Occurring Ammonia and Other Reduced Nitrogen Compounds**
**Possible Effects of Excess Nitrogen Source in Distribution System**
**Proliferation of Some Bacteria Where Nitrogen is Growth-Limiting Nutrient**
**Increased Health Effects Potential**
- Methemoglobinemia
**State of Science on Nitrification Due to Chloramine Formation May Warrant Additional Information**

## Upcoming Activities

**Complete White Paper Development**
**Target Date - February/March, 2002**
**Work with Partners to Complete**
**Circulate to Interested Co-Regulators and Stakeholders**
**Begin Evaluating Potential Distribution System Solutions/Requirements**
**Work with Co-Regulators and Stakeholders to Identify High Priority Issues to be Addressed Through Regulatory Development**

## Contact Information

**Kenneth H. Rotert**
**US EPA**
**1200 Pennsylvania Avenue, NW, Mail Code 4607**
**Washington, DC 20460**
**E-mail: rotert.kenneth@epa.gov**
**Phone: 202-260-5748**