Wastewater treatment systems serving 25 million homes across the U.S. will be improved, due to an agreement between EPA and 14 national organizations. The organizations will work together to improve management of septic wastewater systems by exchanging information and providing technical assistance to their members, states and local municipalities, according to an EPA news release.

Nearly one quarter of the nation’s housing and commercial development depend on onsite and septic wastewater treatment systems. When properly sited, designed, and maintained, these systems perform at a high level. But between 10 and 20 percent fail each year, posing a great threat to surface and groundwater, according to EPA. Malfunctioning systems are the second greatest threat to groundwater quality in the United States.