EPA Updates Water Quality Criterion for Bacteria

E.P.A. Updates a Decades-Old Water Quality Standard

Last week the Environmental Protection Agency issued a new set of water quality guidelines for monitoring bacterial outbreaks in inland and coastal waters used frequently by recreational swimmers. The standard was last updated in 1986. The move was prompted by a federal court order and a requirement of the Beaches Environmental Assessment and Coastal Health Act of 2000.

But the E.P.A. can’t enforce the new standard. It’s up to individual states to decide whether to use the guidelines.

EPA isn't the agency that actually tests and enforces the rules on water quality in most cases.  The states largely adopt EPA's guidelines (or else), but enforcement is in the hands of the states, which can be haphazard, at best (and corrupt at worst).

The new guidelines, based on several health studies, suggest that a wider array of illnesses than previously recognized are caused by the presence of bacteria like E.coli in coastal and inland waters.

This is a really important distinction.  The old bacteria tests only measured E. coli,  the common intestinal bacterium in mammals.The presence of E. coli was assumed to result from human sewage, which was not true in many cases.  However,  they did not discriminate between harmless strains and pathogenic strains, and worse, did not discriminate between E. coli from humans and E. coli from native wildlife. 

A greater problem occurs in salt water, where E. coli does not survive long, but other pathogenic bacteria (like Vibrio cholerae and various other nasty Vibrio) do survive long after the water tests clean for E. coli.

One important new recommendation calls for more frequent testing, every 30 days instead of the current 90 days. The move, Mr. O’Mullan said, is expected to help officials pinpoint and respond more rapidly to the effects of episodic events like flooding or sewage overflows that sully the waters where people swim.

The E.P.A. has also approved a new DNA-based method for water monitoring that is faster than the older method, which takes a full day to process. “It’s particularly frustrating to tell people, ‘Well, we can tell you what the water was like yesterday, but not today,’ ” Mr. O’Mullan said.

The agency’s decision to provide two thresholds for measurements of water quality — a more moderate one that allows for higher concentrations of bacteria in the water, and a stricter marker that deems a more limited concentration of water-borne bacteria acceptable — has drawn criticism from environmental organizations. The groups argue that the two thresholds will encourage states to opt for the less stringent one.

This is a good step, I hope Maryland is one of the states that steps up and adopts the new criteria and the new methods as quickly as possible.