Drinking Water Distribution Systems Assessing and Reducing Risks (2006) / Chapter Skim
Currently Skimming:
2 Regulations, Non-Regulatory Approaches, and Their Limitations
2 Regulations, Non-Regulatory Approaches, and Their Limitations
Pages 47-86
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 47... ...
Prior to the passage of the SDWA, federal involvement in water supply had been limited to development of large multi-purpose water projects and regulation of water quality with respect to interstate carriers. After passage of the SDWA, the federal government became involved in developing national drinking water regulations pursuant to the new law and in conducting research to support these regulations.
|
From page 48... ...
Despite these spatial restrictions, the SDWA does provide EPA with the authority to regulate contaminants within distribution systems -- an authority that EPA has used to promulgate several regulations that address distribution system water quality including the Total Coliform Rule (TCR) , the Lead and Copper Rule (LCR)
|
From page 49... ...
· Prepare a report on the impact of change from conventional treatment of surface water to alternative treatment (membrane) on biofilm growth in water distribution systems in support of regulation development.
|
From page 50... ...
It is the only regulation that is intended to measure the microbiological quality of water within that part of the distribution system controlled by the public water supply. In 1989 EPA promulgated the TCR as a revision to the existing regulation that required public water systems to monitor for coliform organisms in the distribution system.
|
From page 51... ...
. Surface Water Treatment Rule On June 29, 1989, the EPA published the SWTR in response to Congress' mandate to require systems that draw their water from surface water sources (rivers, lakes, and reservoirs)
|
From page 52... ...
States are required to enforce these requirements through state or local codes. Unlike the TCR, which is intended to assess water quality that is representative of the entire distribution system in a dynamic or flowing state, the LCR is predicated on assessing water quality that represents worst case conditions.
|
From page 53... ...
Information Collection Rule In May 1996, EPA promulgated the Information Collection Rule (ICR) , which established monitoring and data reporting requirements for large public water systems including surface water systems serving at least 100,000 people and groundwater systems serving at least 50,000.
|
From page 54... ...
. Interim Enhanced Surface Water Treatment Rule In December 1998, EPA promulgated the Interim Enhanced Surface Water Treatment Rule (IESWTR)
|
From page 55... ...
. Long Term 1 Enhanced Surface Water Treatment Rule In 2002 EPA promulgated the Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR)
|
From page 56... ...
The purpose of the LT2ESWTR is to reduce disease incidence associated with Cryptosporidium and other pathogenic microorganisms in drinking water. The LT2ESWTR supplements existing regulations by targeting additional Cryptosporidium treatment requirements to higher risk systems based on actual monitoring data of source water quality.
|
From page 57... ...
of federal rules and regulations from a distribution system perspective. State Regulatory Programs State regulatory programs that address water distribution systems can vary significantly.
|
From page 58... ...
This Stage 1 standard applies to all community water supplies in the U.S.
|
From page 59... ...
Only a small number of states have requirements for nitrification control and storage tank water quality monitoring. States also use different approaches for establishing these requirements.
|
From page 60... ...
Minimum depth of cover over pipes to 25 7 2 prevent freezing and damage Pressure/leakage testing before placing 26 7 1 new mains into service Disinfection, flushing, and microbial test- 29 5 0 ing before placing new mains into ser vice Looping of pipes/minimization of dead 17 15 2 ends Proper flushing devices at dead ends 23 9 2 Protection of air-release and air vacuum 22 9 1 (1 NR) valves Isolation valves at intersections and over 23 8 3 lengthy stretches of water main Separation of water mains and sanitary 29 4 1 sewers to protect the water main from contamination Protection of water main at surface water 21 11 2 crossings Exterior corrosion protection of water 14 12 8 mains Cross connection control/backflow pre- 29 2 3 vention (through the drinking water program)
|
From page 61... ...
Cross connections occur when a nonpotable water source is connected to a potable water source. Under this condition contaminated water has the potential to flow back into the potable source.
|
From page 62... ...
This survey is not a complete census of all state drinking water programs, rather it is indicative of the practices of the 34 states that responded to the survey. SOURCE: Reprinted, with permission, from ASDWA (2003)
|
From page 63... ...
required to have a program, and the role the states play in implementing and maintaining a program. Some states rely solely on plumbing codes to address cross connections and backflow, which is problematic because plumbing codes, in most cases, do not require testing and follow-up inspections of backflow prevention devices.
|
From page 64... ...
Does the state conduct periodic reviews of cross-connection control programs? 3 Does the state regulation or plumbing code require public education regarding cross-connection control and/or backflow prevention?
|
From page 65... ...
38% SOURCE: Reprinted, with permission, from The American Backflow Prevention Association (ABPA) State Program Survey (1999)
|
From page 66... ...
Thirty-six (36) states have adopted ANSI/NSF Standard 61 by either statute or regulation and thus require water systems to use only water distribution system products, components, and materials that are certified pursuant to the standard.
|
From page 67... ...
, and the National Standard Plumbing Code TABLE 2-8 Plumbing Codes Adopted by the States by 1999 Plumbing Code Number of States Adopting Statewide Code 47 No Statewide Code 3 Statewide Codes Adopted Uniform Plumbing Code 14 State Code 7 International Plumbing Code 5 National Standard Plumbing Code 4 Southern Building Code Congress International 4 Other 13 SOURCE: EPA (2002b)
|
From page 68... ...
Some venting configurations are permitted in one code and not the other. Both the UPC and the IPC include important cross-connection control requirements intended to prevent contamination of the domestic water supply that is internal to the property as well as to the drinking water delivered by the public water system.
|
From page 69... ...
of chlorine Pipe chlorine solution/24 hours or solution/24 hours or 200 ppm for 3 200 ppm for 3 hours; flush hours; flush to purge chlorine; to purge chlorine; bacterio- bacteriological analysis logical analysis Identification of Po- UPC requires color coding IPC requires color coding or metal table and Nonpo- of each system tags table Water Systems Pipe Materials UPC does not require pipe IPC requires pipe material meet material to meet ANSI/NSF ANSI/NSF Standard 61 61 Pipe Placement UPC does not address IPC prohibits placement of water pipe in soils contaminated with contaminants that could adversely affect the pipe Water Supply Protection Requirements Water Supply Well UPC requires 50 feet be- IPC requires 25 feet between waProtection tween water supply wells ter supply wells and sewage dis and sewage disposal sys- posal systems such as septic tanks tems such as septic tanks and 50 feet between water supply and 100 feet between water wells and disposal fields supply wells and disposal fields Note: Where certain entries are blank, the two codes are similar and the small difference is mentioned for only one of the codes.
|
From page 70... ...
In addition, plumbing codes may also be adopted at the local county and municipal level that are at least as stringent as the state plumbing code. For example, in Iowa, the state adopted the UPC as the plumbing code but then amended the UPC to add additional backflow prevention provisions including a requirement that cities with populations of 15,000 or greater enact a backflow prevention program with containment by January 1, 1996.
|
From page 71... ...
All states appear to have provisions for the control of cross connections and/or backflow prevention, although there is considerable variation in how they are implemented and by whom. The majority of states have established regulations within their drinking water programs requiring crossconnection control programs to be implemented by water systems or local authorities, while some have adopted plumbing codes that included the requirements and others have established only guidelines for cross-connection control programs (ASDWA, 2003; EPA, 2002b)
|
From page 72... ...
There also is a significant difference between the approach taken by state drinking water regulatory programs and water systems to ensure high water quality within premises, particularly residential dwellings, versus utility-owned portions of the distribution system. Plumbing codes (UPC and IPC)
|
From page 73... ...
VOLUNTARY AND NON-REGULATORY PROGRAMS THAT INFLUENCE DISTRIBUTION SYSTEM INTEGRITY Voluntary and non-regulatory programs exist that are designed to provide public water systems with approaches for maintaining and improving distribution system integrity. There are several objectives of these non-regulatory water quality improvement programs for water supplies, foremost among them being to further protect public health and to engage in risk management efforts beyond what is provided by federal, state, and local regulations and the enforcement system developed for primacy agencies.
|
From page 74... ...
Note that the Partnership for Safe Water and QualServe, two voluntary AWWA programs that target drinking water quality, are not discussed because distribution systems are not their primary focus. QualServe uses self-assessment and peer-review methods to identify opportunities for improvement in water and wastewater utility services, while the Partnership for Safe Water focuses on water treatment plant optimization.
|
From page 75... ...
Distribution system management activities listed in the standard include system pressure monitoring, backflow prevention, permeation prevention, water loss minimization, valve exercising and replacement, fire hydrant maintenance and testing, maintenance of coatings and linings, water use metering, external corrosion control, water quality monitoring, and energy management. The verification step of the standard includes providing certain required documents and records.
|
From page 76... ...
The participating utilities found that the implementation of HACCP to water supply distribution was feasible and practical, but that the time and resource requirements were greater than originally anticipated. The development of the HACCP plan was useful in honing in on the most important risks and process controls for water quality management.
|
From page 77... ...
Programs like HACCP are ideally suited to industries that experience little variation on a day-to-day basis (such as food and beverage processing plants) and are not as easily adapted to the dynamic nature of drinking water distribution systems that may experience changes in water quality depending on season, source of supply, and changing daily demands.
|
From page 78... ...
The interdisciplinary HACCP team consisted primarily of inhouse staff: the water quality manager, the water laboratory supervisor, an engineer continues
|
From page 79... ...
Originally, the utility thought that HACCP would involve identifying critical flow paths within the distribution system and monitoring these flow paths more intensively to assure water quality to downstream sites. Instead, by nature of the selected hazards, the measures used to control these hazards focused on operations and maintenance activities rather than water quality monitoring.
|
From page 80... ...
a management plan that documents the system assessment, control measures, monitoring plan, corrective action procedures to address water quality incidents, communication plan, and supporting programs such as standard operating procedures, employee training, and risk communication. Both HACCP and Water Safety Plans should be used continuously.
|
From page 81... ...
In cases where contractors are used to repair or maintain the infrastructure (for example, many utilities allow certified plumbers to perform the tasks related to backflow prevention and cross-connection control) , diligence of construction inspectors in providing oversight is of paramount importance because the contractor may or may not be following standard practices.
|
From page 82... ...
Finally, while existing certification exams test generic knowledge, future requirements should ensure that operators understand the system in which they work and are familiar with portions of operating plans that apply to performance of their daily activities. CONCLUSIONS AND RECOMMENDATIONS The Total Coliform Rule, the Surface Water Treatment Rule, the Disinfectants/ Disinfection By-Products Rule, and the Lead and Copper Rule are the federal regulations that address water quality within the distribution system, and they do so in a piecemeal fashion.
|
From page 83... ...
Existing plumbing codes should be consolidated into one uniform national code. Although similar with regard to cross-connection control requirements and other premise plumbing protection measures, the two principal plumbing codes that are used nationally, the UPC and the IPC, have different contents and permit different materials and devices.
|
From page 84... ...
1998b. National Primary Drinking Water Regulations; Interim Enhanced Surface Water Treatment Rule; Final Rule.
|
From page 85... ...
2006b. National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water Treatment Rule, Final Rule.
|
From page 86... ...
2004. Guidelines for drinking water quality, third edition.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.