Wastewater may not be sexy – quite the opposite – but it sure is big news around here these days. Falmouth recently approved a town-wide comprehensive wastewater management plan calling for hundreds of millions of dollars in spending to install sewer systems in parts of town that surround coastal bays particularly hard-hit by nutrient pollution from septic systems. And Falmouth is far from alone; towns across the Cape and Islands are struggling with how to fund wastewater treatment systems that are the backbone of efforts to meet federally-mandated reductions in nutrient pollution.
But not everyone is convinced that costly centralized sewer systems are the way to go. At a recent forum hosted by the Waquoit Bay National Estuarine Research Reserve, experts discussed the options. Elise Hugus says they fall into four categories:
- The Big Pipe Method: This includes conventional centralized wastewater treatment plants, but also individual “on-site” systems and cluster or satellite systems that collect and treat waste from a smaller group of homes. Although costly, such options may end up being the most cost-effective and also offer the greatest opportunity to address non-nutrient pollutants, such as pharmaceuticals and household products, that are emerging as potential environmental and health concerns.
- Innovative and Alternative Systems: From augmented septic systems to composting or urine-separating toilets, there are many options for individual homeowners to reduce the flow of nutrients out of their backyards. However, getting all homeowners to install, maintain, and properly operate such systems could be a logistical (and financial) nightmare.
- The Shellfish Solution: Shellfish aquaculture can act as a natural water filtration system, feeding on the algae that bloom in response to elevated nutrient levels. The added bonus here is the potential economic benefit of a commercially viable food product. But it’s not a panacea. The number of oysters or quahogs needed to completely filter a pond or bay might get in the way of other activities. And uptake of pharmaceuticals by shellfish might be a concern.
- Flushing the Bays: Drawing on the old adage that “dilution is the solution to pollution,” one possibility is widening the inlets that connect coastal ponds to the ocean. This option only works if tides are large enough to flush the bay well. It also comes at the expense of barrier beaches and the unique ecosystems of the Cape’s coastal ponds, which have evolved with restricted contact with the ocean.
Bottom line: there is no ace in the hole. All of the options have their strengths, their limitations, and their costs. But we have a full deck of options. The trick will be putting cards together to make a winning hand.