Alternative Wastewater Solutions

All across the country, private citizens, developers, and government officials are turning to eco-toilets to save water. These environmentally friendly toilets use much less water—in some cases, none at all—and turn waste into compost.

No-water toilets in a busy setting like a stadium can save millions of gallons of water a year. But the toilets might also better isolate chemicals that have the potential to harm human health, and Silent Spring Institute wants to find out.

Silent Spring researchers have long studied contaminants of emerging concern (CECs): excreted hormones, pharmaceuticals, and consumer product chemicals that are washed down household drains and toilets but for which no regulations currently exist. The Institute has detected these chemicals, which raise concerns about human health, in Cape Cod ponds and drinking water. Institute scientists have also found that several of these chemicals pass through septic systems and sewage plants unchanged. The treated water from these sources often ends up in areas that feed local drinking water wells.

Because eco-toilets process waste on-site without using much water, they offer a potential method for reducing groundwater contamination. On Cape Cod, MA, towns such as Falmouth are considering the toilets to help address nutrient pollution that causes damaging algal blooms. No study, however, has investigated the potential of eco-toilets to reduce CEC contamination.

In the new research project, Silent Spring Institute is testing household wastewater in Falmouth homes before and after eco-toilet installation. The project aims to answer several questions. To what extent can eco-toilets divert pharmaceuticals and hormones, which typically end up in toilets, from entering groundwater? Do they divert consumer product chemicals that are usually washed down drains? What are the potential benefits of eco-toilets in reducing chemical inputs into local groundwater and drinking water? Such information can help officials design more comprehensive solutions to address both nutrient and CEC pollution on Cape Cod and beyond.

Funding for this study comes from Massachusetts Environmental Trust and private donations.

Massachusetts Environmental Trust