Houston has a sewage problem. In the last five years, the city has self-reported more than 9,300 instances of untreated sewage overflowing from its sewer systems. The foul, bacteria-laden mixture often ends up in the city’s bayous and other waterways, where it increases the risk of illness for humans who come in contact and has toxic effects on aquatic life.

The leaks, which disproportionately occur in poor and minority communities, are nothing new: In the last 30 years, taxpayers have pumped $3 billion into upgrading Houston’s wastewater infrastructure, according to city officials. In 2005, the city reached an agreement with the Texas Commission on Environmental Quality (TCEQ) to prevent the unauthorized discharge of sewage. As part of the agreement, the city spent $755 million on replacing and upgrading sewer lines over the next decade.