宾夕法尼亚州环境保护部（DEP）启动了全州安全饮用水过滤厂性能评估（FPPE）计划，并在290个地表水处理厂完成了506个FPPE。1988年该项目开始时，只有39%的核电站的性能被评为可接受，但到1996年，这一比例已增至91%——这表明对这些系统的帮助可以带来成功的改进，并降低水传播原生动物的风险。成品水中隐孢子虫阳性（假定）样本的百分比从1990年的35%降至1996年的5%。 隐孢子虫阳性样本在过去五年中一直低于5%。颗粒计数数据的第90百分位显示，在3-18um大小范围内，过滤后的颗粒计数为50/mL，这是可接受性能的阈值。由于FPPE计划的目标是优化性能，因此3-18um颗粒的浓度应保持在10/mL以下，以尽量减少致病性原生动物的突破。环境保护署认为浊度为<0。每个过滤器1个ntu，作为过滤器设备性能的最佳水平。包括10个参考文献、表格和图表。

Pennsylvania's Department of Environmental Protection (DEP) initiated a statewide filter plant performance evaluation (FPPE) program for safe drinking water and completed 506 FPPEs at 290 surface water treatment plants. Only 39 percent of the plants were rated acceptable for performance at the program's inception in 1988, but by 1996 the percentage had increased to 91 percent -demonstrating that assistance to these systems could lead to successful improvements and decreased risks from waterborne protozoa. The percentage of positive Cryptosporidium (presumptive) samples of the finished water dropped from 35 percent in 1990 to <5 percent in 1996. Positive Cryptosporidium samples have remained below 5 percent in the last five years. The 90th percentile of particle count data showed a postfiltration count of 50/mL in the 3- to 18-um size range as the threshold for acceptable performance. Because optimized performance is a goal of the FPPE program, the concentrations of 3- to 18-um particles should remain below 10/mL to minimize breakthrough of pathogenic protozoa. The DEP considers turbidity of <0.1 ntu from each filter as a more optimum level of filter plant performance. Includes 10 references, table, figures.