Nebraska Regional Sanitary Landfill

Location: Stanton County, Neb.

Client: Northeast Nebraska Solid Waste Coalition

Burns & McDonnell was retained by the Northeast Nebraska Solid Waste Coalition to assist in siting, designing and starting up a new landfill, including preparation of a landfill disposal rate study.

Burns & McDonnell has also prepared construction drawings and performed construction management and quality assurance services in the different phases of landfill development. These services include the installation of the groundwater drainage system, installation of soil liner, geomembrane liner and the leachate collection system.

Studies and Investigations

Five potential new landfill sites were initially investigated. The criteria used to select the optimum site included geologic conditions (available soil and relative groundwater location), geographic location (accessibility, isolation, and haul distance), landfill operation impacts (noise, traffic, visual aesthetics) and socioeconomic impacts (land use, real estate costs, site improvements).

Burns & McDonnell recommended a site in Stanton County, Neb., where an environmentally sound sanitary landfill could be designed, constructed and operated in accordance with Subtitle D requirements. Burns & McDonnell then completed a thorough hydrogeologic investigation of the site.

Upon completion of the hydrogeologic investigation, Burns & McDonnell designed a 200-ton-per-day facility complete with a collection office and scales, a maintenance building, site utilities, siltation ponds, drainage structures and screening berms.

Subsequent to the design of the facility, Burns & McDonnell performed a landfill disposal rate study for the new Subtitle D landfill. The tipping fee for the landfill was calculated on a per-ton basis to cover pre-development costs, capital debt service, landfill construction costs, operations and maintenance, closure, and post-closure costs. Total annual costs were calculated over the projected life of the facility, approximately 35 years.

The construction costs were separated to correspond to the different landfill development phases over the life of the landfill. These costs were broken down into initial development and specific facility areas, and then into seven construction phases between 1994 and 2025. The construction cost evaluation consisted of various construction tasks, each with associated unit costs. Estimated quantities and costs were included for each task by construction phase. Material availability, transportation and regional material costs were also taken into account when necessary. Annual costs were calculated using capital recovery factors. The annual operations costs were also evaluated so that the coalition could assess the required fees to adequately fund the landfill operations. These costs included fixed and variable operating fees, administrative costs, building repairs, professional services, leachate treatment, groundwater monitoring and gas monitoring.

The closure costs involved calculating the costs to close the landfill in a series of phases corresponding to the landfill areas. The annual cost for each area was calculated as the series of annual cash flow requirements to accumulate the closure cost over the time period from the initial operation to the closure of the area.

The post-closure costs included the costs involved with inspecting the site, final cover repair, seeding repair, fence repair, groundwater monitoring, leachate collection and treatment, gas monitoring, and recordkeeping. The financial requirements for post-closure activities were estimated and incorporated as cash flow requirements during the active life of the landfill.

Finally, a study was undertaken to investigate potential future impacts on the tipping fee. The study looked into the effects that future population growth would have on the regional landfill and on tipping fees.

Regional Planning

Burns & McDonnell was retained by the Northeast Nebraska Solid Waste Coalition to prepare an integrated solid waste management plan for its 17 municipal and county members. The development of the plan involved the design of a solid waste planning questionnaire which was completed by each of the coalition members. The questionnaire required a description of the solid waste jurisdiction area, existing solid waste management system information, and solid waste planning goals and objectives.

Burns & McDonnell reviewed the completed questionnaires and interviewed members of each jurisdiction to obtain complete data. A plan component for each jurisdiction was then produced addressing the following topics:

  • Background information
  • Existing solid waste management system
  • Solid waste quantities and characteristics
  • Waste volume reduction goals
  • Solid waste management objectives
  • Future solid waste disposal

The solid waste management plan addressed an overall information policy for the coalition, regional solid waste disposal, and a general evaluation of solid waste management alternatives. The plan also identified waste reduction and reuse, drop-off recycling and yard waste composting as technically and economically feasible future alternatives for additional diversion of waste from the coalition’s proposed 30-year sanitary landfill. The general plan component and the individual jurisdiction component were reviewed in public meetings sponsored by each of the solid waste jurisdictions. The plan was reviewed by the Nebraska Department of Environmental Quality.

Permitting and Design

The Subtitle D landfill design included the optimization of soil balance, access roads, surface drainage controls, a geomembrane liner system, subsurface groundwater drains, leachate collection and storage, gas and groundwater monitoring programs, final topography, and landfilling operations.

The landfill liner system designed by Burns & McDonnell for this facility included a 60-mil high density polyethylene (HDPE) geomembrane liner and a 2-foot clay liner. In areas where the landfill excavation was below a perched water zone, a subsurface groundwater drain was designed to prevent the groundwater zone outside the landfill from recharging the soil beneath the landfill bottom. Water collected in the groundwater drainage system as well as stormwater diverted and collected from the landfill is collected in a sediment basin before it is allowed to discharge offsite. Leachate generated by the landfill is collected and spray-irrigated onto sections of the landfill that have received intermediate cover to contribute to an increased rate of leachate evaporation, waste decomposition and landfill gas production. Any leachate that is not spray-irrigated is collected and hauled offsite to the Norfolk wastewater treatment plant.

The landfill cap system was designed to include a 60-mil HDPE geomembrane liner and a compacted soil infiltration layer underneath a lateral drainage layer and a vegetative layer.

Compliance Monitoring

Burns & McDonnell developed a groundwater monitoring plan for the Northeast Nebraska Solid Waste Coalition Regional Sanitary Landfill. The groundwater monitoring plan summarizes the geologic and hydrogeologic data pertaining to the site, and outlines the monitoring well system and other relevant background information. The plan provides instructions for completing the field sampling, laboratory analysis, reporting, data validation and statistical analysis. In addition, field personnel installed dedicated monitoring systems in the shallow and deep monitoring wells.

Burns & McDonnell provided background groundwater quality monitoring services to the Northeast Nebraska Solid Waste Coalition Regional Sanitary Landfill. A team of professionals experienced in groundwater issues combined their efforts to complete the variety of tasks associated with detection groundwater monitoring. Burns & McDonnell assembled the database of analytical data to be used during future groundwater monitoring events in the statistical evaluation of the groundwater data.

Construction Services

Burns & McDonnell prepared the construction documents and associated engineering drawings for Phases I through IV of the landfill and has provided the coalition with assistance during the bidding phase of the project. Burns & McDonnell provides construction services including field oversight, approval of submittals and construction quality assurance for each landfill cell.