WSP10395 - Laserfiche WebLink

Home Browse Search

01111 J 8 ~l Due to the need and requirements for selenium reduction, cost effectiveness and minimized activity in the project area, only the preferred alternative was evaluated in detail. Other alternatives considered but eliminated from further review because they did not meet the purpose and need or were not cost effective included: . No Action Alternative - Did not meet the need. Construct New Wetlands and Dilute - was not cost effective. Replace Habitat Offsite - Did not meet the need. Divert and Dilute - would disrupt wildlife and have more extensive operation and maintenance needs. . . . Reclamation has selected Alternative 2 - Pipe and Dilute, as the recommended alternative. This alternative is presented as the preferred alternative in the draft and final Environmental Assessments (EAs). Under the recommended alternative, selenium contaminated return flows from two surface drains would be diverted away from the East backwater directly to the Colorado River through buried pipelines. The water discharged directly into the river would mix and be diluted by the much larger river volume. A flushing channel would be cut to route clean river water to dilute selenium concentrations in the West backwater. Mitigation for lost habitat would involve new habitat improvements within the OMW A or at another location along the Colorado River. The estimated construction cost of the recommended alternative would be approximately $83,000 and annual expenditures for operation and maintenance would be about $6.000. The National Irrigation Water Quality Program will provide the funding for construction and maintenance of the project. Reclamation will be responsible for perfonning the operation and maintenance work or identifying an appropriate contractor. Conclusions: Under the No Action Alternative, high selenium concentrations in two backwater areas would continue to pose risks to fish and aquatic birds. This would not meet the need and purpose as described above. In tenTIS of environmental consequences associated with implementing the recommended alternative, there would be no change in water use or diversions. In addition, cultural resources, Indian Trust Assets, and Environmental Justice would not be affected by the recommended action. All pennits and contracts would have a "stop work" clause in the event that cultural or paleontological resources are found during construction. Surface surveys showed no sites. All temporary roads and access pointS would be recontoured and reseeded to reduce erosion. No new permanent roads would be established. All specifications would include provisions to reduce erosion, restore landscapes, and provide for revegetation.