Environmental Assessment and Finding of No Significant Impact: Wastewater Treatment Capability Upgrade, Project NO. 96-D-122 Pantex Plant Amarillo, Texas

This Environmental Assessment (EA) addresses the U.S. Department of Energy (DOE) proposed action regarding an upgrade of the Pantex Plant Wastewater Treatment Facility (WWTF). Potential environmental consequences associated with the proposed action and alternative actions are provided. DOE proposes to design, build, and operate a new WWTF, consistent with the requirements of Title 30 of the Texas Administrative Code (TAC), Chapter 317, ''Design Criteria for Sewage Systems,'' capable of supporting current and future wastewater treatment requirements of the Plant. Wastewater treatment at Pantex must provide sufficient operational flexibility to meet Pantex Plant's anticipated future needs, including potential Plant mission changes, alternative effluent uses, and wastewater discharge permit requirements. Treated wastewater effluent and non-regulated water maybe used for irrigation on DOE-owned agricultural land. Five factors support the need for DOE action: (1) The current WWTF operation has the potential for inconsistent permit compliance. (2) The existing WWTF lies completely within the 100-year floodplain. (3) The Pantex Plant mission has the potential to change, requiring infrastructure changes to the facility. (4) The life expectancy of the existing facility would be nearing its end by the time a new facility is constructed. (5) The treated wastewater effluent and non-regulated water would have a beneficial agricultural use through irrigation. Evaluation during the internal scoping led to the conclusion that the following factors are present and of concern at the proposed action site on Pantex Plant: (1) Periodic wastewater effluent permit exceedances; (2) Wetlands protection and floodplain management; (3) Capability of the existing facility to meet anticipated future needs of Pantex (4) Existing facility design life; and (5) Use of treated wastewater effluent and non-regulated water for irrigation. Evaluation during the internal scoping led to the conclusion that the following conditions are not present, nor of concern at the proposed site on Pantex Plant, and no further analysis was conducted: (1) State or national parks, forests, or other conservation areas; (2) Wild and scenic rivers; (3) Natural resources, such as timber, range, soils, minerals; (4) Properties of historic, archeological, or architectural significance; (5) Native American concerns; (6) Minority and low-income populations; and (7) Prime or unique farmland. In this document, DOE describes the proposed action and a reasonable range of alternatives to the proposed action, including the ''No-Action'' alternative. The proposed action cited in the ''U.S. Department of Energy Application for a Texas Pollutant Discharge Elimination System Permit Modifying Permit to Dispose of Waste, No. 02296,'' December 1998, included the construction of a new wastewater treatment facility, a new irrigation storage pond, and the conversion of the current wastewater treatment facility into an irrigation storage pond. Although a permit modification application has been filed, if a decision on this EA necessitates it, an amendment to the permit application would be made. The permit application would be required for any of the alternatives and the filing does not preclude or predetermine selection of an alternative considered by this EA. This permit change would allow Pantex to land-dispose treated wastewater by irrigating agricultural land. This construction for the proposed action would include designing two new lagoons for wastewater treatment. One of the lagoons could function as a facultative lagoon for treatment of wastewater. The second lagoon would serve as an irrigation storage impoundment (storage pond), with the alternative use as a facultative lagoon if the first lagoon is out of service for any reason. The new facultative lagoon and irrigation water storage pond would be sited outside of the 100-year flood plain. The existing WWTF lagoon would be used as a storage pond for treated wastewater effluent for irrigation water, as needed. The two new lagoons would be linked by pipeline. This proposed construction would disturb approximately 8 acres. Potential environmental consequences of each action have been identified and evaluated. References used and agencies, organizations, and persons contacted are listed