Cape Cod evokes images of quaint villages, lighthouses, and the seaside. While much of the Western U.S. faces water vulnerability, it is favored with ample water resources, both salt and freshwater. However, studies have shown for years that many of those water sources are polluted, threatening some of the defining qualities of the peninsula and impacting its economy. The fourth annual State of the Waters: Cape Cod report revealed that the quality of surface water has degraded in each of the last three years, with 87 percent of the area’s coastal embayments having excess nutrients this past year, an increase of nearly ten percent since the previous year.[1]

For over a decade, the Conservation Law Foundation (CFL) filed federal lawsuits arguing unsuccessfully that the overabundance of nitrogen and phosphorous are primarily the result of poorly treated wastewater from residential septic tanks; the wastewater makes its way into the Cape’s estuaries resulting in harmful algal and cyanobacteria. In June 2021, CFL changed tactics and sued the Massachusetts Department of Environmental Protection (MassDEP) and the towns of Barnstable and Mashpee in Massachusetts Superior Court. CFL argued that MassDEP admits Title 5 septic systems which don’t remove enough nitrogen yet allows approval for such systems, thereby in defiance of its own regulations.

Now, MassDEP has introduced Title 5 amendments to reduce pollution in "Nitrogen Sensitive Areas” as a proposed lawsuit settlement. The new regulations would require residents in the affected areas to upgrade their septic systems within five years unless their community chooses to address the issue for all. Those communities must apply for a 20-year watershed permit to build new networks of public sewer lines that would reduce nitrogen pollution.

Neither option is cheap. If homeowners are forced to replace or upgrade their septic system, the cost could be as much as $35,000. The cost for a community to install a new sewage system will obviously be much higher as seen in Mashpee, the town currently in the process of building a sewer system that is projected to cost as much as $450 million.[2] Although it is not clear who would be ultimately responsible for the costs to meet the requirements of the proposed amendments, funds could come from taxes collected on vacation rentals, from federal and state funds, or from increased property taxes.

MassDEP’s Title 5 amendments were open for public written comment through the end of January, and final regulations are said to be released this year.

[1] “Overview.” State of the Waters: Cape Cod, 26 Jan. 2023, https://capecodwaters.org/overview/#results.

[2] Flavelle, Christopher, and Sophie Park. “A Toxic Stew on Cape Cod: Human Waste and Warming Water.” The New York Times, The New York Times, 1 Jan. 2023, https://www.nytimes.com/2023/01/01/climate/cape-cod-algae-septic.html.