Summary

EPA is issuing a notice of proposed action under the Clean Water Act to reopen a National Pollutant Discharge Elimination System (NPDES) permit NN0020290 issued to the Navajo Tribal Utility Authority (NTUA) Tuba City Wastewater Treatment Facility located in Coconino County, Arizona, within the Western portion of the Navajo Nation.

In a letter dated February 16, 2018, NTUA requested relocating the compliance sampling point for the above referenced Facility to a sampling point located just west of the chlorine contact chamber instead of closer to the receiving water. The reason for this requested change in sampling location was that the current location lacks electrical power and requires manual sampling collection. The proposed new location has access to electrical power allowing for the use of an automatic sampler. The new location, unlike the previous location, is also behind a property fence and thus provides added security for the relatively expensive automatic sampling equipment. NTUA provided all necessary information, including the precise latitude and longitude of the new sampling location, as well as schematics and photographs of the proposed new location. EPA agrees that this new location is substantially equivalent to the previous sampling location and therefore EPA is re-opening the permit to make just this specific change and is soliciting comments on just this specific change in the permit. No other change is being made to the existing permit.