Summary

EPA is issuing a notice of proposed action under the Clean Water Act. EPA is proposing to issue a National Pollutant Discharge Elimination System (NPDES) permit (No. NN0020265) to Navajo Tribal Utility Authority (NTUA) for the Chinle wastewater treatment plant located in northern Arizona’s Apache County on the Navajo reservation, approximately 300 feet east of Highway 191 and 1.8 miles from NTUA’s Chinle District Office.

The NTUA facility, currently undergoing construction and renovation, serves a population of approximately 4,500 and receives domestic sewage with a design flow capacity of 0.45 million gallons per day. The lagoon system provides secondary treatment which consists of a one-inch bar screen, a grit chamber, a lagoon with aeration, a 9-inch Parshall flume flow meter, and a chlorine contact chamber for disinfection, followed by sodium sulfite gas injection for de-chlorination. The proposed permit will regulate the discharge of treated effluent from the lagoon treatment facility to Nazlini Wash, a tributary to Chinle Wash, an eventual tributary to San Juan River.

***Please bring the foregoing notice to the attention of all persons who would be interested in this matter. ***