how many wastewater treatment plants are there in the us
Publicly owned treatment works There are over 16,000 POTWs in the U.S., serving 75 percent of the total population.[4] The remainder of the population is served by decentralized or private septic systems. The POTWs treat 32Â billion US gallons (120 gigalitres) of wastewater every day.[5] Most POTWs are required to meet national secondary treatment standards.[6][7]