Davis & Floyd, Inc. has designed wastewater facilities for many municipalities, military installations, and industries in the Southeast. These facilities range in size from a few hundred thousand gallons per day to over 40 MGD.

The projects include wastewater collection sewers, interceptor and trunk sewers, and treatment plants. In many cases, pump stations and force mains are part of the project. In areas where there is little natural gradient, pump stations and lines become very large. Often, almost all of the wastewater requires one or more pump station lifts before reaching the treatment plant.

A few examples of our municipal wastewater projects are:

Basewide Wastewater Treatment Systems Upgrade, Marine Corps Base, Camp Lejeune, N.C.

This project involved the design of eight submersible sewage pump stations to receive raw wastewater from developed areas of Camp Lejeune and transport to a central treatment facility. The pump stations ranged in size from 0.5 mgd to 8.2 mgd (3-0.5 mgd, 2-0.7 mgd, 1-3.8 mgd, 1-5.3 mgd, and 1-8.2 mgd) with redundant pumps for reliability as well as full-time emergency power capability.

The stations are comprised of reinforced concrete wetwells for the pumps with an upper level covered by grating for personnel operations. Adjacent to the wetwells at each location is a brick and block, one-story building to house the electrical switchgear, emergency generator, and station operations.

The stations are equipped with macerators; chemical feed systems for odor control; monorails with hoists; automatic and remote electronic controls; utilities; access roads; fencing; and other site improvements. The location and geology of the site required incorporation of extensive dewatering and foundation features into the design. The largest wetwell, which was approximately 800 SF in area, was designed utilizing 25 ton timber piles for primary bearing support.

Approximately 226,190 LF, or 43 miles, of force mains connect the stations. The breakdown of this pressure pipe includes 7,500 LF of 8-inch; 70,690 LF of 10-inch; 30,200 LF of 14-inch; 38,800 LF of 16-inch; 16,600 LF of 18-inch; 8,500 LF of 20-inch; and 53,900 LF of 24-inch pipe. Approximately 5,000 LF of the 8-inch and 24-inch were installed beneath rivers and the Intercoastal Waterway utilizing horizontal directional drilling techniques.

Horse Creek Regional Wastewater Treatment Plant.

This award winning project is designed to serve a large area in Aiken County, South Carolina, and includes a 20 MGD treatment plant and extensive major trunk facilities. Construction of these facilities eliminated the pollution in Horse Creek which had become one of the most polluted streams in the Southeast.

North Charleston Sewer District, North Charleston, S.C.

Serving the North Charleston Sewer District for many years, we expanded and upgraded a treatment plant from 18 MGD to 27 MGD, planning for a subsequent increase to 4l MGD. Other projects for the NCSD include major trunk lines, pump stations, and force mains. Sewer line work in coastal areas such as Charleston is complicated by flat terrain, relatively high ground water elevation, and difficult soil conditions.