Biological Consulting Services of North Central Florida, Inc.

Long Term Enhanced Surface Water Treatment Rule (LT2ESWTR)

Previous drinking water regulations required public water systems that use surface water sources to remove at least 99% (2-logs) of Cryptosporidium by filtration. New data on Cryptosporidium infectivity, occurrence, and treatment indicate that, while these treatment requirements were adequate for most water treatment facilities, there are a subset of systems that utilize source waters with high levels of Cryptosporidium oocysts and also systems that do not provide filtration. It is these systems that are of particular concern for water quality managers and public health officials.

As a result, the Environmental Protection Agency (EPA) has promulgated the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESTWR), which increases monitoring requirements for all treatment facilities that use surface water or ground water under the direct influence of surface water.

The LT2 rule requires large surface water treatment facilities (those serving >10,000 individuals) and unfiltered systems to monitor for Cryptosporidium in their effluent at least once per month for a period of 2 years.

BCS is an EPA certified LT2 laboratory and can accept either 10 L or 50 L water samples for analysis mandated by the EPA Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). Our laboratory is completely equipped for environmental parasitology and possesses all the equipment necessary for performing EPA Method 1623 for analysis of Cryptosporidium and Giardia.  In addition to detection of Cryptosporidium and Giardia by Method 1623, BCS has a full-scale cell culture laboratory, which enables viability testing of Cryptosporidium oocysts. Viability is assessed and the number of infectious oocysts can be estimated using methods outlined in published literature (Slifko et al., 1999).