Wastewater Collection System Master Plan

Diamondhead Water and Sewer District, 

Wastewater Collection System Master Plan

Service Type: 

In March 2004, the Diamondhead Water and Sewer District hired Carollo to develop an immediate response to EPA Region 4’s Cease and Desist Order, dated September 2002. The present Diamondhead collection system commonly experiences peaking factors in excess of six times the dry weather flows. System outflows are often experienced.

Carollo immediately initiated direct communications with EPA. A response package was delivered on April 15, 2004, that details the District’s programs for Continuing Sewer Assessment, Rehabilitation of the Collection System, and Rehabilitation of the Wastewater Pumping Stations. Carollo also developed and submitted draft versions of a comprehensive Operations and Maintenance Manual for the complete collection system.

Coinciding with the Cease and Desist Order Response Effort, the District, Carollo, and Carollo’s prime subconsultant, Pipeline Analysis, LLP, planned and initiated a field assessment program to identify the location and degree of infiltration and inflow (I/I) that is being experienced. Flow monitoring has identified the top 25 percent of the collection system that experiences excessive I/I. These top culprits are presently being investigated with smoke testing, manhole investigations, and closed circuit televising. In conjunction with the pipeline and manhole evaluations, Carollo is preparing a comprehensive evaluation of the system’s 34 lift stations and will determine an upgrade and expansion plan for the lift stations.

The findings of these investigations will direct the team to develop a planning document that outlines needed repairs, upgrades and expansions to the system to accomplish I/I reduction goals ranging from 25% to 45%. This planning effort will develop an immediate upgrade program for the next two years, a short-term five year program and a 20-year long-term expansion program. Carollo is preparing a dynamic hydraulic model of the system that will provide documentation of the benefit for each implemented improvement and upgrade to the system.

In the areas of data collection and document management, Carollo is developing data input forms that will allow the District’s staff to enter field observations and reports immediately. These observations and reports will be directly linked with the City’s GIS system and will be available for field recovery and use.

The District and Carollo are jointly pursuing financing packages with both state and federal grant and loan programs.

Carollo prepared a response package detailing the Districts programs for a continuing sewer assessment program rehabilitation of the collection system, and rehabilitation of the wastewater pumping stations.