Summary

EPA is issuing a notice of proposed action under the Clean Water Act (CWA) to reopen a National Pollutant Discharge Elimination System (NPDES) permit NN0030343 issued to the Navajo Tribal Utility Authority (NTUA) Northern Edge Navajo Casino Wastewater Treatment Plant located in Upper Fruitland, San Juan County, New Mexico, in the Navajo Nation.

Following the issuance of the renewal permit for the above referenced facility, in a letter dated August 3, 2017, NTUA requested to decrease the monitoring frequency for Whole Effluent Toxicity (WET) from quarterly to semi-annually. In support of this request NTUA presented monitoring data for the last four years, which show no exceedances of the WET limit. Considering the nature of the effluent treatment at the facility and the level of treatment achieved by the facility EPA agrees that this reduced frequency of WET monitoring is justified. Therefore, EPA is re-opening Part II. Section C.1. to make this change and is soliciting comments on just this specific section of the permit.