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Water: Microbial & Disinfection Byproducts Rules

Final Long Term 1 Enhanced Surface Water Treatment Rule

EPA 815-F-02-001
January 2002

F • A • C • T • S • H • E • E • T

EPA has finalized the Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR). The purposes of the LT1ESWTR are to improve control of microbial pathogens, specifically the protozoan Cryptosporidium, in drinking water, and address risk trade-offs with disinfection byproducts. The rule was published in the Federal Register on January 14th, 2002. ( read online ) ~ ( PDF )

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The rule will require certain public water systems to meet strengthened filtration requirements. It will also require systems to calculate levels of microbial inactivation to ensure that microbial protection is not jeopardized if systems make changes to comply with requirements of the Stage 1 Disinfectants and Disinfection Byproducts Rule (Stage 1-DBPR). This rule, which addresses subpart H systems serving fewer than 10,000 persons, builds upon the framework established for larger systems in the Interim Enhanced Surface Water Treatment Rule (IESWTR).

Which public water systems must comply with the rule?

The LT1ESWTR applies to all public water systems that:

  • use surface water or ground water under the direct influence of surface water (GWUDI); and
  • serve fewer than 10,000 persons.

The rule is expected to apply to more than 11,000 systems that serve nearly 18.5 million Americans.

What does the rule require?

The LT1ESWTR provisions fall into the four following categories:

1) Cryptosporidium Removal

  • All systems must achieve a 2-log removal (99 percent) of Cryptosporidium.

2) Enhanced Filtration Requirements

  • Filtered systems must comply with strengthened combined filter effluent (CFE) turbidity performance requirements to assure 2-log removal of Cryptosporidium; and
  • Conventional and direct filtration systems must continuously monitor the turbidity of individual filters and comply with follow-up activities based on this monitoring.

3) Microbial Inactivation Benchmarking

  • Systems will be required to develop a profile of microbial inactivation levels unless they perform monitoring which demonstrates their disinfection byproduct levels are less than 80 percent of the maximum contaminant levels (MCLs) established in the Stage 1 DBPR; and
  • Systems considering making a significant change to their disinfection practice must determine their current lowest level of microbial inactivation and consult with the state for approval prior to implementing the change.

4) Other Requirements

  • Finished water reservoirs for which construction begins 60 days after promulgation of the rule must be covered; and
  • Unfiltered systems must comply with updated watershed control requirements that add Cryptosporidium as a pathogen of concern.

These requirements were developed based on the IESWTR, but have been modified to reduce the burden on small systems.

How soon will the changes take effect?

The rule is effective 30 days after publication in the Federal Register; however, each of the requirements has a different compliance date. The table below provides the applicable dates.

Rule Requirement Compliance Date
New reservoirs must be covered 60 days after LT1ESWTR promulgation
Systems 500 or greater begin to develop profile July 1, 2003
Systems < 500 begin to develop profile January 1, 2004
2-log Cryptosporidium removal 3 years after LT1ESWTR promulgation
New CFE Turbidity Limits 3 years after LT1ESWTR promulgation
Individual Filter Turbidity Monitoring 3 years after LT1ESWTR promulgation
Unfiltered systems must meet updated watershed control requirements 3 years after LT1ESWTR promulgation

What is the significance of this rule?

In 1990, the Science Advisory Board (SAB) cited drinking water contamination as one of the most important environmental risks and indicated that disease-causing microbiological contaminants (i.e., pathogens such as, bacteria, protozoa, and viruses) are probably the greatest remaining health risk management challenge for drinking water suppliers. The final LT1ESWTR addresses this challenge by improving the control of microbiological pathogens such as Cryptosporidium in public drinking water systems serving fewer than 10,000 persons. It will also protect the public against increases in risk from such pathogens in cases where systems alter their disinfection practices to meet new disinfection byproduct standards promulgated under the Stage 1 Disinfectants and Disinfection Byproducts Rule (DBPR).

The final LT1ESWTR is part of the larger Microbial and Disinfection Byproducts (M-DBP) cluster of rules. These rules include the IESWTR and the Stage 1 DBPR, which were promulgated on December 16, 1998. Implementing the provisions contained in the LT1ESWTR will provide protections against the potentially lethal microorganism Cryptosporidium and Giardra to persons served by small public water systems using surface waters. The IESWTR afforded the 165 million people served by large water systems added protection against Cryptosporidium. The LT1ESWTR completes this effort by extending protection to the remaining 18.5 million Americans served by smaller public water systems.

How will this rule protect public health?

EPA has determined that the presence of microbiological pathogens in public water supplies is a health concern. If finished water supplies contain microbiological contaminants, illnesses and disease outbreaks may result. Twelve waterborne cryptosporidiosis outbreaks caused by contamination in public water systems were reported to the Center for Disease Control and Prevention between 1984 and 1998. In 1993, Cryptosporidium caused more than 400,000 people in Milwaukee, WI, to experience intestinal illness. More than 4,000 were hospitalized and at least 50 deaths were attributed to this cryptosporidiosis outbreak. Other recent cryptosporidiosis outbreaks attributable to public water system contamination occurred in Nevada, Oregon, and Georgia.

The IESWTR set enforceable drinking water treatment technique requirements to reduce the risk of Cryptosporidium from surface water for systems serving at least 10,000 persons. The LT1ESWTR extends further this necessary protection from Cryptosporidium to communities of fewer than 10,000 persons.

Today's rule for the first time establishes Cryptosporidium control requirements for systems serving less than 10,000 persons by requiring a minimum 2-log removal for Cryptosporidium. The rule also strengthens filter performance requirements to ensure 2-log Cryptosporidium removal, establishes individual filter monitoring to minimize poor performance in individual units, includes Cryptosporidium in the definition of GWUDI, and explicitly considers unfiltered system watershed control provisions.

The rule also reflects a commitment to the importance of maintaining existing levels of microbial protection in public water systems as plants take steps to comply with newly applicable DBP standards. Systems considering significant changes to their disinfection practices must first evaluate current levels of Giardia inactivation (and virus inactivation if applicable) and consult with their state primacy agency for approval before implementing those changes. Thus, compliance with the provisions of the rule will improve public health protection by reducing the risk of exposure to Cryptosporidium in small systems serving fewer than 10,000 people even as those systems begin to take steps to comply with related DBP standards.

How much will this rule cost?

In estimating the costs of the LT1ESWTR, the Agency considered impacts on PWSs and States (including territories and EPA implementation in non-primacy States). The LT1ESWTR will result in increased costs to public water systems for implementing the components of the rule. States will also incur implementation costs. EPA estimates that the annual cost of the rule will be $39.5 million.

Approximately 84 percent ($33.1 million) of the rule's total annual costs are imposed on drinking water utilities. States incur the remaining 16 percent ($6.4 million annually) of the LT1ESWTR's total annual cost. The turbidity provisions, which include treatment changes, monitoring and reporting, account for the largest portion of the total rule costs ($37.7 million annually). Systems will incur most of the turbidity provision costs. The national estimate of annual system costs is based on estimates of system-level costs for the rule and estimates of the number of systems expected to incur each type of cost.

The average annual household cost is estimated to be $6.24 per year. Ninety percent of households will experience costs of less than $15 per year, and fewer than one percent of households are estimated to incur annual costs of greater than $120 per year; however, this estimate is conservative because systems with fewer households are likely to choose less costly improvements.

What are the benefits of this rule?

The primary benefits of today's final rule come from reductions in the risk of illness from pathogens in drinking water. In particular, the LT1ESWTR focuses on reducing the risk associated with disinfection-resistant pathogens, such as Cryptosporidium. Other pathogens may also be removed more efficiently due to implementation of these provisions. Exposure to other pathogenic protozoa or other waterborne bacterial or viral pathogens are likely to be reduced by the provisions of this rule as well. In addition to preventing illnesses, this rule is expected to have other non-health related benefits. These benefits result from avoiding non-health related costs associated with waterborne disease outbreaks.

The annual monetized benefits of the proposed rule are conservatively calculated to be $18.9-$90.9 million. EPA estimates that implementation of the LT1ESWTR will result in a reduction of cryptosporidiosis illness of between 12,000 and 41,000 cases per year, and a reduction in mortalities due to cryptosporidiosis of between 1 and 5 deaths per year. Most of the avoided deaths would be among immunocompromised and other sensitive subpopulations.

Is funding available to help systems comply with this rule?

Since 1996, the Drinking Water State Revolving Loan Fund has made over $4.4 billion available to states, which have used the funding to provide loans to help water systems improve their infrastructure. Through December 31, 2000, states had made close to 1,600 loans for more than $3.2 billion. Other federal funds for infrastructure financing are available through the U. S. Department of Housing and Urban Development's Community Development Block Grant Program and the Rural Utilities Service of the U.S. Department of Agriculture. EPA also provides program management funding to states that have primary enforcement responsibility for their drinking water programs through the Public Water Systems Supervision (PWSS) grants program.

How did EPA consult with stakeholders in developing this rule?

EPA began outreach efforts to develop the LT1ESWTR in the summer of 1998 with two public meetings: one in Denver, Colorado and the other in Dallas, Texas. Building on these two public meetings, EPA held a number of additional meetings with stakeholders, trade associations, environmental groups, and representatives of state and local elected officials. Of particular importance to this rule, given its focus on small systems, EPA received valuable input from small entity representatives who were consulted in accordance with the Small Business Regulatory Enforcement Fairness Act (SBREFA). The Small Business Advocacy Review Panel was initiated in April of 1998 and officially convened in August of 1998. Many of the Panel's recommendations are reflected in today's rule.

EPA provided numerous opportunities for stakeholder and public involvement. In June 1999, EPA mailed an informal draft of the LT1ESWTR preamble to the approximately 100 stakeholders who attended either of the public stakeholder meetings. Members of trade associations and the small entity representatives consulted in accordance with SBREFA also received the draft preamble. EPA receivedvaluable suggestions and stakeholder input from 15 state representatives, trade associations, environmental interest groups, and individual stakeholders. EPA proposed the LT1ESWTR on April 10, 2000. During the comment period, the Agency held a public meeting in Washington, DC, on April 14, 2000. Additionally, the proposed rule was presented to industry, state representatives, and the public in nearly 50 meetings across the US, including a May 30, 2000 meeting in Washington, DC, with ten representatives of elected state and local officials. Finally, EPA mailed approximately 200 copies of the proposed rule to stakeholders.

Where can the public get more information about this final rule?

For general information on the LT1ESWTR, contact the Safe Drinking Water Hotline, at (800) 426-4791, or visit the EPA Safewater website, www.epa.gov/safewater/mdbp/lt1eswtr.html. For copies of the Federal Register notice of the final regulation or technical fact sheets, contact the Safe Drinking Water Hotline at (800) 426-4791. The Safe Drinking Water Hotline is open Monday through Friday, excluding Federal holidays, from 9:00 a.m. to 5:30 p.m. Eastern Time.


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