Union County - Countywide Water Transmission System

In April 1999, the Arkansas legislature passed Act No. 1050 authorizing the creation of groundwater conservation boards in counties designated as "critical groundwater areas." The first county to form such a board was Union County in south central Arkansas, bordering Louisiana. A U.S. Geological Survey monitoring well near the center of the county recorded a static water level in 1942 of 60 feet above sea level. By 1999, the static level in the same well had dropped to 180 feet below sea level. This represents an average depletion of 4.2 feet per year over the 57 years of records.

Burns & McDonnell prepared a master plan and performed the design and construction observation of most of the recommended facilities. The project included a 65-million-gallon-per-day (MGD) river intake, 48-inch raw water pipeline, 32.5-MGD water treatment facility, and a 48-inch pipeline to a merchant power plant being developed by Panda Energy. Burns & McDonnell completed a 30 percent design of these facilities and turned the drawings over to Panda Energy, who completed the work on a design-build basis. The transmission system to serve local industries around El Dorado, Ark., was designed by Burns & McDonnell and constructed on a design-bid-build basis for the Union County Water Conservation Board. The industrial transmission system includes a 3-MG reservoir, pump station, and industrial metering stations.

The transmission system to support the delivery of non-potable water for the industrial users includes 14-miles of pipeline ranging in size from 48-inch to 12-inch. Design and permit considerations included state roadway crossings, railroad crossings, lake crossings and wetland construction issues. The pipeline alignment was selected with consideration being given to existing development and the ability to construct the pipeline. Most of the pipeline alignment is parallel to overhead power transmission systems. Temporary construction area was provided on the power line right-of-way with specific safety requirements stipulated by the power utility. Permanent easements for pipeline and temporary construction easements were less costly when obtained adjacent to existing cleared easements in this heavily timbered county.

Construction in wetland areas was closely monitored and provisions were provided to assure that the in situ material was segregated and replaced within the same strata. The natural flow of water in the wetland was maintained across the work area. Temporary fill material was allowed, however it had to be removed within 90 days following installation of the pipeline. This prevented permanent damage to the wetland and assured that minimal disturbance had occurred.

• Ground storage and booster pump
• 1 mile of 48-inch raw water line
• 4.5 miles of 48-inch non-potable water line
• 14 miles of 12-inch  to 48-inch non-potable water line
• 3-MG reservoir and booster pump station
• Three industrial metering facilities
• Regulatory approvals