Detecting Human Sources of Surface Water Contamination at the EPA Region 1 Laboratory
by Peter Philbrook , chemist , EPA Region 1 Laboratory and Todd Borci , environmental scientist , EPA Region 1 Office of Environmental Stewardship
The US Environmental Protection Agency ( EPA ) Region 1 Laboratory supports all New England states and 10 tribal nations and has two primary purposes : to provide state-of-the-art monitoring , evaluation and technical expertise to EPA , state , tribal and other partners ; and to provide environmental monitoring , analytical support and data assessments to its internal and external customers . This is typically done in support of national regulations , such as the Clean Water Act , that may be enforced or investigated at the EPA regional headquarters level .
What Clean Water Act problem were you facing in EPA Region 1 ?
The bacterial impairment of surface water which exceeds minimum water quality criteria . The criteria are based on the use of two bacterial indicators of fecal contamination , E . coli and enterococci . Exceedances trigger investigations into the source , and , if found to be of human origin , preventative measures that remediate the problem area ( s ) are required . Human sources are targeted because they represent a higherrisk health threat and typically the solution can be engineered . One of the major sources of contamination is aging urban sewage infrastructure that discharges to storm drains and nearby surface waters . Identifying , locating and removing sources of human sewage that impair waterways is critically important to EPA ’ s mission to ensure compliance with the Clean Water Act .
High bacteria concentrations were found in this urban waterway . Additional chemical testing revealed high levels of surfactants / ammonia / chloride and pharmaceuticals , which indicated the presence of human sewage and initiated further investigation for remediation purposes . Photo by Todd Borci
These two protocols , combined with microbial testing , give investigators more definitive information to use when making decisions on impacted waterways .
What new laboratory and field methods did you develop to find a viable solution ?
In 2009 , our field investigators and chemists worked together to focus on determining whether bacteria found in surface waters originated from human sanitary sewage . This effort resulted in two new chemical procedures by the EPA Region 1 Laboratory that are used to definitively track sources of human waste in surface water . The first is a practical , low-cost suite of chemical screening kits for surfactants , ammonia and chloride that identify problem spots while in the field . Surfactants represent the presence of soaps / detergents , ammonia is found at high concentrations in untreated human sewage and chloride indicates the source is a chlorinated water system . The second is a laboratory procedure that forensically identifies and quantifies human pharmaceutical compounds using high-performance liquid chromatography with tandem mass spectrometry ( HPLC / MS / MS ). We look for caffeine , acetaminophen , cotinine , atenolol , metoprolol , 1,7-dimethylxanthine and carbamazepine . These two protocols , combined with microbial testing , gives investigators more definitive information to use when making decisions on impacted waterways . It also allows Region 1 to delineate problem drainage areas faster and with greater accuracy , and has given investigators convincing source tracking evidence when pursuing enforcement actions .
How is this positively impacting the region ?
As we near our eighth year using this protocol , we have made significant strides in getting sewage out of stormwater throughout New England . For instance , the direct use of this protocol in Boston Harbor has eliminated over 68 million gallons of raw sewage annually which would have otherwise entered the harbor and associated watersheds .
Given this and other experiences , how would you recommend that public health / environmental laboratories face this or other source tracking problems ?
The HPLC / MS / MS method we developed incorporates multiple automated sample prep steps which streamlines the process , reduces time and minimizes solvent usage . This , along with an abbreviated target compound list , also significantly reduces analysis cost . Implementation of this method may take approximately 30 days and only several commercial laboratories currently offer this analysis in the US . If more laboratories offered the test , costs would be driven down and municipalities would be more likely to use this to detect sewer leaks .
What are your future source tracking plans ?
The field work and investigative / detective piece of source tracking is by far the most important aspect of this project . As we better learn the method advantages and limits , we are able to tackle more complex projects , such as areas with frequent beach closures and other chronic bacterial impairments . We continually strive to train and inform our partners on how to implement this tool and are also constantly looking into new technologies to help us accomplish our mission .
The beach stormwater outfall above discharges into a saltwater marsh . High bacteria concentrations were found here , but chemical indicators showed no evidence of sewage contamination
For more information on these source tracking techniques and methods , please contact Peter Philbrook at Philbrook . Peter @ epa . gov .
LAB MATTERS Winter 2017
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