Wastewater Performance Anxiety

Earlier this month, the Coalition for Buzzards Bay went public with information about the performance of Falmouth’s wastewater management facility. Had not they not requested this information from the DEP, we would not have known that elevated nitrogen levels are being discharged from the facility to West Falmouth Harbor.  This is the kind of oversight that the media and environmental watchdogs will have to do in order to ensure that nitrogen limits are being met, no matter which wastewater treatment route is taken in the future.

As the graph shows, nitrogen output from the Blacksmith Shop Road wastewater treatment facility was very high, from the day it was built in 1994.

But even after a $15 million upgrade designed to reduce nitrogen output to 3 mg/liter– which worked well in 2006– periodic spikes have led to an average nitrogen discharge of 5 mg/liter over the last three years.

Averages aside, at times, those spikes have approached 20 mg/liter.  It’s not the sort of performance taxpayers might expect from an expensive upgrade to advanced treatment technology. And it won’t do much to improve conditions at Meshapaquit Creek, the area of West Falmouth Harbor most heavily impacted by a nitrogen plume emanating from the facility.

Let there be light

It’s a shame that we didn’t hear about the problems three years ago, when they started happening. But now that the information has come to light, town officials have started talking, and a contract is underway with the plant’s designer. Hopefully we will see a return to safer nutrient outputs to the harbor, which a Massachusetts Estuary Project study reported could recover, if the Total Maximum Daily Load for nitrogen is limited to 3.5 mg/liter.

In all fairness, the fine people in the wastewater department have been working hard to address the problem. The fact that the spikes tend to happen in the winter indicates that cold temperatures are making it hard for denitrifying bacteria to do their jobs. And they have been working without the benefit of advice from the new facility’s engineer, due to litigation with the designer, Maguire.

Also, to be fair, many of the benefits of the upgrade cannot be used at the current flow to the treatment facility. Because the plant handles just 3% of the town’s wastewater (the percentage of town that is sewered, not including New Silver Beach), it is operating at less than half its 1 million gallons-per-day capacity.  At these low-flow rates, the plant cannot use its denitrifying technology to do more than filter out solids. In addition, the plant accepts septage hauled in from the town’s septic tanks. So, it is handling highly concentrated influent without the benefit of technology designed to treat larger volumes of wastewater.

Permitting Pollution

Another bureaucratic snafu helps the wastewater department save face. Despite the 2005 upgrade, the treatment facility has been operating under a DEP groundwater recharge permit, which expired in 2002. The town applied for a new one on time, but has yet to hear from state environmental authorities.

Under that permit, the facility is performing beautifully. The out-dated guidelines suggest a maximum nitrogen output of 50 mg/liter and 810,000 gallons per day discharge.

One of the reasons that the DEP might not have issued a new permit yet, said the wastewater superintendent, Jerry Potamis, is that they can’t figure out how to regulate a maximum daily limits for nitrogen (the TMDLs) in a groundwater discharge permit. Falmouth’s facility is somewhat unique in that it discharges to the groundwater, but it is also a coastal community subject to state-mandated TMDLs.  Perhaps the DEP could use Falmouth as a study, as other towns seek to build treatment plants and recharge the effluent to the aquifer.

The whole situation makes me wonder who residents are supposed to trust, while swallowing multi-million dollar bills to improve our municipal wastewater treatment system. If the state regulators cannot get their act together, and non-profit advocacy groups are the only ones doing oversight, how will Falmouth residents know that a $600 million investment is doing the job it is supposed to? Right now, the only pressure towns feel to meet TMDL targets is from the Conservation Law Foundation, the group that sued the City of Boston, resulting in the effective, yet expensive, cleanup of Boston Harbor. With the recession on in full swing, it is unlikely that the state will be cracking the whip to enforce the MEP guidelines. Meanwhile, estuarine decline is in advanced stages in coastal ponds around the Cape. Eel grass and abundant shellfish beds may be distant memories by the time anything changes.

This entry was posted on Thursday, March 25th, 2010 at 11:32 am and is filed under Sewering, Wastewater. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

The views and opinions in the Enterprise blogs are those of the author and are not neccessarily shared by Falmouth Publishing.