A watershed is a land area from which all surface and ground water flows to a common water body, like a pond or a bay. Everyone lives in a watershed.
Our daily activities on the watershed (showering, laundry, flushing) contribute wastewater to our ground water (our drinking water source) and to our surface waters (ponds, lakes, bays)
We release almost 7 billion gallons of wastewater each year via septic systems on Cape Cod. This wastewater flows to our groundwater and then to our coastal waters.
Estuaries are partially enclosed coastal bays where salt water and freshwater mix. Cape Cod has several dozen estuaries. They are critical habitat for important fish and shellfish, like winter flounder and scallops.
The seagrass meadows in our estuaries, and the fish and shellfish that inhabit them are important to our environment and economy.
Eelgrass is the name of the seagrass we find in our Cape Cod estuaries. It is a flowering plant with leaves, roots and seeds that just happens to live submerged.
SEAGRASS is not the same as SEAWEED. Seaweed is a kind of algae, a very simple organism that also lives underwater.
Algae can be microscopic (phytoplankton or microalgae) or macroscopic (seaweed or macroalgae).
Some algae, both micro and macroscopic species, can grow very quickly when a source of nutrients appears. They can out-compete other species like seagrasses, and take over the area.
The main reason behind the loss of seagrasses and the decline of coastal water quality is an excess delivery of nitrogen (mainly in the form of nitrate) to our coastal waters.
Most of the nitrate comes from our household septic systems. (Fertilizer use is a much smaller contributor to coastal water degradation.)
All septic systems discharge nitrogen, even Title 5 systems. Title 5 systems were designed to remove bacteria and viruses, not nitrogen.
Nitrogen is essential to all living organisms. It is too much nitrogen that is causing the problem of eutrophication.
Rapid population growth is adding more septic systems and therefore more nitrogen to our groundwater and bays.
To restore health to our bays, we must dramatically reduce the amount of nitrogen entering them. To do so, we cannot continue to just dispose of wastewater. We must treat our wastewater.
Cape Communities need to develop Comprehensive Wastewater Management Plans. These plans must be integrated with land use planning (zoning), or else the placement of wastewater infrastructure may lead to growth in the wrong areas.
Wastewater management solutions could include treatment plants of different sizes in some areas like town centers, neighborhoods, cluster developments); changing zoning to direct growth to certain areas and away from other areas; and developing plans to manage on site systems, includingany denitrifying on-site systems that are used.
Treating wastewater adequately to protect the health of our coastal bays will be expensive.
No matter where we live on Cape Cod, each of us contributes nitrogen to groundwater and coastal bays. We are all part of the problem and must be all part of the solution.
Wastewater moves across town boundaries. Many coastal bays and their watersheds are in more than one town. Devising plans to remove nitrogen from a shared coastal bay will require cooperation from the towns in the contributing watershed.
Community members need to support town actions that integrate local and regional solutions.
The decline of coastal water quality from too much nitrogen from on-site septic systems is the most serious water quality problem facing Cape Cod!