Water Quality:

An Evaluation Method for the Construction Grants Program--Methodology

PEMD-87-4A: Published: Dec 17, 1986. Publicly Released: Dec 17, 1986.

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GAO evaluated existing Environmental Protection Agency (EPA) data concerning the Construction Grants Program's effectiveness in upgrading sewage-treatment plants in order to develop guidelines to evaluate the upgrades.

GAO found that: (1) adequate stream data to assess the effect of treatment plant upgrades do not yet exist; and (2) using existing data would provide a more realistic estimate of the program's effectiveness than is now available. GAO developed a method which successfully answered essential evaluation questions with available data and software. GAO found that: (1) there were statistically significant post-upgrade decreases in the pollutants discharged from each plant that it examined and improvements in downstream water quality in three of the four cases; (2) for the most part, changes in plant discharge were moderately reflected in stream water quality; and (3) a correlation between changes in a plant's discharge levels and stream indicators does not mean that the plant's upgrade is the sole determinant of a change in water quality downstream.

Recommendation for Executive Action

  1. Status: Closed - Implemented

    Comments: EPA has upgraded the quality and usability of its databases, and has examined the feasibility of broad-based GGP evaluation.

    Recommendation: The Administrator, EPA, should perform additional evaluations of treatment plant upgrades that use available data and methods similar to those GAO developed. These evaluations should be intended to determine the feasibility of performing a broadly based and methodologically sound evaluation of the Construction Grants Program that makes optimal use of the data already in EPA possession and that identifies and remedies the gaps in its information systems. EPA should improve the reliability and accessibility of its water quality database by ensuring the internal consistency of its data collection practices, updating its data on the geographical locations of plants and stations to reflect changes in them, and expanding its use of river mile indicators for monitoring stations and point sources.

    Agency Affected: Environmental Protection Agency


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