Contact: Terry Black,
Portland Water Bureau
(503) 823-1168
terry.black@ci.portland.or.us
November 16, 2009
PORTLAND OR—The Portland Water Bureau has submitted a detailed water quality sampling plan and study to the U.S. Environmental Protection Agency (EPA) with the intention of collecting data over the next year to demonstrate whether the microbial contaminant, Cryptosporidium, is a health risk to Portland drinking water customers. The study will be used to support the City’s application to EPA for a variance to a new federal drinking water regulation that otherwise requires the city to construct a $99 million ultraviolet (UV) treatment plant.
“We’re glad to finally be moving forward with a data collection plan that will address the technical requirements of the EPA,” said Water Bureau Administrator David G. Shaff. “We’ve seen nothing historically to suggest that Cryptosporidium is a public health risk in the Bull Run watershed. We hope this sampling plan and study will verify that and help us make a good case to EPA.”
The central feature of the city’s plan is a rigorous water quality sampling program to evaluate the concentration and types of Cryptosporidium that may be present where raw water first enters the Portland water system. Two supplemental elements are also included based on extensive feedback and discussion with EPA. The first is a water quality sampling plan to determine whether or not and to what degree so called “hot spots” might exist throughout the watershed where significant Cryptosporidium could theoretically occur. The second is a plan for adapting, if feasible, a computer model for use in evaluating the theoretical concentration and movement of Cryptosporidium and other microbial pathogens in the Bull Run watershed.
Also included in the plan is critical supplemental information detailing the quality of the Bull Run source including historic monitoring data, natural watershed conditions, source water protections and watershed controls.
Background.
In January 2006 the EPA issued the Long Term 2 Enhanced Surface Water Treatment Rule (LT2) rule in accordance with the Safe Drinking Water Act. The purpose of the rule is to reduce illness linked with Cryptosporidium, a micro-organism (protozoan) naturally present in bodies of surface water throughout the world and which sickened thousands and killed over 100 people in a 1993 waterborne outbreak in Milwaukee, Wisconsin. Surface water supplies are particularly vulnerable if, unlike the Portland’s Bull Run supply, they regularly receive runoff or pollution from human or animal wastes. Compliance with this portion of the rule for Portland would require the construction of a new water treatment facility to either remove or inactivate Cryptosporidium.
Cryptosporidium can enter surface water via human and animal fecal material. Surface water sources that are exposed to intensive human activities, pollution and animal wastes are most likely to contain the parasite. Portland’s source water, the Bull Run River, is within an exceptionally protected watershed far removed from the types of human activities and pollution that are associated with the presence Cryptosporidium. There are no sewage systems or cattle present anywhere near Portland's source water in the federally protected Bull Run watershed. The wildlife that inhabit the Bull Run watershed pose the only potential source of Cryptosporidium. Because of this, the city only rarely detects Cryptosporidium in the Bull Run when it conducts regular water quality monitoring and only at extremely low levels. Cryptosporidium has not been detected in Portland’s monthly drinking water samples since September 2002.
The Portland City Council committed in January 2005 to pursue alternative forms of compliance for the LT2 rule. Soon after, the city met with EPA officials to encourage the agency to alter the final rule so that it would include alternate approaches that would allow Portland to avoid building additional treatment. When that effort failed, the city filed a legal challenge to the rule in the United States Court of Appeals for the District of Columbia Circuit in early 2006. In November 2007 the court issued a decision rejecting the city’s challenge and upholding the rule.
Since the court decision, the city has been pursuing parallel compliance strategies. The Portland City Council earlier this year directed the Water Bureau to begin planning and budgeting to design a UV treatment plant in accordance with the LT2 rule which requires that additional treatment be in place by April 1, 2014. In addition, the Council directed the bureau to continue its attempts to obtain a variance to the rule. A variance could conceivably enable the bureau to avoid the expenses associated with building a new treatment plant if the city can demonstrate that due to the nature of the Bull Run source, additional treatment is unnecessary. EPA rejected two prior variance sampling proposals by the city, the last one in March 2009. Over the course of the last eight months, Water Bureau staff have worked directly with EPA officials to address the technical issues and specific direction the agency has provided.
The Water Bureau intends to commence its variance sampling plan and study as soon as possible so that a year’s worth of raw water sampling data and supplemental information can be collected by the time the UV facility design is completed. At that point, the city will need to commit to either constructing the UV treatment facility or implementing approved variance monitoring procedures. Should the water quality testing results prove favorable, the city could conceivably apply for a variance to EPA by the end of 2010.
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