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The Maryland Department of the Environment’s (MDE) Water Supply Program (WSP) is considered one of the leaders in state drinking water programs, for promoting optimization of surface water filtration plants. An optimized plant, whether publicly or privately owned, consistently produces high quality finished water that exceeds standards, regardless of the raw water quality. The goal is to see that each unit process is individually optimized, creating a multiple barrier against passing protozoan cysts such as Giardia and Cryptosporidium, a public health threat that can cause gastrointestinal illness. These parasites can be transmitted through ingestion of fecally contaminated water or food.
An optimized plant provides greater protection of public health than a plant that is only meeting the finished water quality standards. During the outbreak of cryptosporidiosis that occurred in Milwaukee in 1993, which killed over 100 people and sickened 400,000, the plant was meeting all applicable water quality standards.
Evaluating Performance Means Overall Safety
WSP’s primary method for promoting optimization has been the Comprehensive Performance Evaluation (CPE). The CPE, developed by U.S. Environmental Protection Agency (EPA) in 1989, consists of three steps:
The process takes a team of three or four WSP engineers approximately three days on-site to complete. It requires additional time to collect data prior to the CPE and to draft the report following the CPE. The plant’s administration, design, operation, and maintenance practices are evaluated. Water quality data from the previous year is also evaluated, and the team identifies factors that prevent the plant from achieving optimized performance. Turbidity, which is a measurement of the cloudiness of water, is the primary indicator of a plant performance. Low turbidity water presents less risk of passing disease-causing microorganisms into the finished water.
The WSP began conducting evaluations in 1990. A CPE has been performed at least once at nearly all of Maryland’s surface water filtration plants, and will continue to be performed at a rate of about four a year. CPEs have prompted many Maryland’s filtration plants to improve their operational practices or to construct capital improvements. The following graphs show one Maryland plant’s improved settled and finished water performance after a performed CPE.
In 2003, the WSP joined with other EPA Region 3 states to form an Area Wide Optimization Program (AWOP). AWOP was developed as a process to help states focus their resources where they will be of most benefit. As a part of AWOP, each participating state develops a method for assessing and comparing surface water plants using the same measures. Using this assessment, the state can target plants that are most in need of technical assistance or training. The quarterly AWOP meetings also provide states with new technical assistance techniques and information sharing among peers.
Another tool, called Performance Based Training, introduced to Region 3 states in 2005, encourages improved performance at several plants at the same time. Performance Based Training takes operators from three to six plants and provides five training sessions spread out over 12 to 15 months. The sessions are typically spaced three months apart. In the interim period, the operators must apply the concepts taught in the previous classes to complete homework assignments. The beginning of the next session starts with each plant presenting the results of their homework to the other participating plants. This framework encourages participants to incorporate new practices into their routine plant operation. The sessions also provide operators with leadership skills, and with techniques that they can experiment with and problem-solve at their own plant without always relying on outside help. In July 2006, a round of Performance Based Training was started in Region 3, with two plants from Maryland, and one plant each from Pennsylvania, Virginia, and West Virginia. Plants in other states have shown sustained improved performance after completing the training and we are confident that similar outcomes will be the result in Maryland.
The Comprehensive Performance Evaluations are a catalyst for improving performance of drinking water filtration plants. MDE’s Water Supply Program continues its commitment to stay at the forefront of public health protection with new initiatives such as Performance Based Training.
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