What do you get when you have an antiquated sewage treatment plant near clams, mussels, and oysters? The answer: shellfish that may not be safe to eat. Responding to the results of a joint dye study with the Food and Drug Administration, the NH Department of Environmental Services (NHDES) has immediately closed and/or restricted the taking of shellfish from new areas of the Great Bay-Piscataqua River estuary that were previously open to recreational harvesting.
In the past, the Peirce Island sewage plant in Portsmouth, New Hampshire, has occasionally failed to adequately chlorinate the discharge into the Piscataqua River. Out of abundant caution, the NHDES has established safety zones where shellfish harvesting is forbidden in order to protect public health. Substituting a dye for bacteria, the study showed that the travel time was quicker and the distribution greater – and that the concentration levels would be more serious than previously thought. In addition to bacteria, significant virus levels present in the Portmouth plant are also of great concern.
Upgrading to a higher level of treatment will dramatically reduce the virus levels. Delay equals continued and unnecessary pollution – 1,300 more tons every year than the standard under the Clean Water Act. In my recent opinion piece in The Portsmouth Herald, I call on the City of Portsmouth to finally solve this problem and join every other sewage treatment plant in New Hampshire that has upgraded to secondary treatment levels.