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Water: Drinking Water Standards

Treatment Technology

The mission of the treatment technology team is to identify and/or develop high quality, cost-effective treatment technologies to meet regulation development and program implementation objectives and deadlines. The short-term goals are to meet the statutory requirements to publish lists of technologies for the existing regulations. The long-term goals include identifying small system technologies for future regulations and updating the existing lists to incorporate new technologies.

Timetable for Short-term Goals

August 1997 Compliance Technology List for Surface Water Treatment Rule
August 1998 Compliance Technology List for other National Primary Drinking Water Regulations
August 1998 Variance Technology List for National Primary Drinking Water Regulations


The Safe Drinking Water Act, as amended August 6, 1996, directs EPA to make technology assessments for three categories of small public water systems. EPA must perform these technology assessments for all of the regulated contaminants. In August 1997, EPA issued a guidance manual entitled "Small System Compliance Technology List for the Surface Water Treatment Rule," available online at https://www.epa.gov/safewater/regs/swtrlist.html.

Within two years after enactment, EPA must issue a list of technologies that can achieve compliance with existing National Primary Drinking Water Regulations (NPDWRs) for the other regulated contaminants. When these technologies cannot be identified, EPA must identify affordable technologies that maximize contaminant reduction and protect public health (variance technologies). The list of variance technologies is also due within two years after enactment.

Small System Solutions

The new requirements provide a focus for identifying small system solutions. Through the process of identifying appropriate technologies, EPA will improve the informational base for making treatment decisions, and simplify the process for identifying circumstances for the appropriate use of variances. The treatment technologies can incorporate the limitations faced by small systems, which can include: lack of expertise in operating complex treatment technologies, lack of full-time operator, and lack of a large customer base to lessen the impact on individual water bills.

The new requirements will provide small systems with options designed specifically for their use. This should aid in the implementation of the regulations because smaller systems may be able to successfully install and operate treatment technologies to achieve compliance. When systems cannot achieve compliance, they can apply for small system variances that will improve public health protection at an affordable cost.

Detail of Activity

June 1997
Examine the current treatment technology cost equations to determine which technology/waste disposal options may qualify as small system treatment technologies. The bases for the technology cost equations in the Very Small Systems Best Available Technology Cost Document, the Water Model, and the Small Water System Byproducts Treatment and Disposal Cost Document will be reviewed to identify central treatment/waste disposal option candidates for the three size categories. Costs for model systems for each of the three size categories will be compared with the national-level affordability criteria to determine if affordable compliance technologies exist for the regulated contaminants.


Sept 1997
Develop criteria for national-level affordability that will be used to identify affordable compliance or variance technologies. The national-level affordability criteria will be used to determine when variance technologies and small system variances are available. The options being evaluated include comparisons to other utilities, other alternatives, median household income, and infrastructure costs versus water quality. The existing baseline of expenditures by customers in small water systems is also being summarized. A draft report will be available for the May 1998 stakeholder meeting.


October 1997
Examine full-scale data for systems serving less than 10,000 people to assess treatment performance and cost. The treatment technology data on 200 sites in National Drinking Water Clearinghouse's RESULTS database will be examined and updated to assess technology cost and performance. Other full-scale data in the literature will also be summarized. All of the cost data will be updated to a common-year basis for comparison with the current cost models.


April 1998
Update RESULTS database to incorporate treatment technology data on 500 additional systems and to expand the searchable fields in the existing database. RESULTS 2.0 has data on approximately 200 water systems. Population served is not a searchable field in RESULTS 2.0. The updated RESULTS database will include population served as a searchable field and will incorporate the data on another 500 systems that has been received since the release of RESULTS 2.0.


April 1997
April 1998
Develop cost equations for Point-of-Use and Point-of-entry devices and determine the ranges of applicability. The ranges of applicability (number of households) will be determined for point-of-use and point-of-entry devices. Cost equations will be developed for all of these options to compare with the national-level affordability criteria. A final draft report on POU and POE devices will be discussed at the May 1998 stakeholder meeting.


August 1998 Publish Small System Compliance Technology Lists, to present options for small systems regarding National Primary Drinking Water Regulations set prior to the 1996 Amendments to the Safe Drinking Water Act.


EPA encourages public comment on treatment technology issues. Public stakeholder meetings are posted on the Office of Ground Water and Drinking Water website at https://www.epa.gov/safewater/ https://www.epa.gov/safewater/cal1031.html. Meeting summaries are posted at https://www.epa.gov/safewater/ndwacsum.html.

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