Waste Management
Skyline Landfill, TCEQ Permit No. MWS-42D
Dallas and Ellis Counties, Texas

Overview
Biggs and Mathews has provided professional engineering, hydrogeologic characterizations, and construction phase services at the Skyline Landfill located in Dallas County. The professional services provided include permitting, geology and hydrogeology, environmental services, planning, engineering design, and construction management for numerous projects. Projects have included revisions to the permit, construction of liners, leachate collection systems, stormwater control facilities, final covers, access roads, and equipment maintenance facilities. The success of these projects are based on solid communication with Waste Management in the decision process for permitting and design approach and establishing construction budgets. The continued professional relationship with Waste Management and Biggs and Mathews demonstrates a professional commitment to the long-term success of the Waste Management’s Skyline Landfill.

Permitting
The Biggs and Mathews project team, consisting of the engineer of record, geologist of record, and geotechnical engineer of record, have prepared numerous municipal solid waste permit modifications and a major permit amendment for the Skyline Landfill. The permit projects included civil engineering design, geotechnical engineering, and regulatory coordination. The permit modifications have included revisions to excavation grades and leachate collection system, sequence of development, cost estimates for closure and postclosure care, monitoring systems, sampling and analysis plans, site operating plans and surface water management facilities.  The permit amendment provides a major redesign and vertical expansion of the facility.

Geology and Hydrogeology
In response to the 2006 TCEQ rule revisions to Subchapter J – Groundwater Monitoring and Corrective Action, Biggs and Mathews completed permit modifications for the facility’s groundwater monitoring program and groundwater sampling and analysis plan to comply with the revised rules.  The facility groundwater monitoring system was re-evaluated including identification and evaluation of the following: the uppermost aquifer, groundwater flow direction and rate, potential impacts of operational attributes of the facility on groundwater flow, impacts to critical receptors, and the appropriate spacing, locations and screened intervals of groundwater monitoring wells. 

Environmental Services
Biggs and Mathews provided installation of groundwater monitoring wells and landfill gas probes at the site.  A comprehensive nature and extent study was conducted in response to statistical exceedances and an alternate source demonstration was submitted and approved.  We continue to provide comprehensive environmental services including groundwater sampling, analytical laboratory testing, statistical analysis and reporting.

Planning
Biggs and Mathews provides routine airspace estimates, airspace usage projections and optimization studies, interim fill and grading plans, and erosion control plans for the Skyline Landfill.  We also provide evaluations and cost projections for the future development of the waste fill and soil borrow areas.

Engineering Design
Biggs and Mathews has provided engineering design and construction documents for Subtitle D lined cells and alternative water balance final covers at the Skyline Landfill.  We have also provided the design and construction documents for site improvements such as internal roads, drainage facilities, parking areas, enhanced wildlife habitats and equipment maintenance facilities.

Construction Management

Biggs and Mathews has managed the construction of over $12,000,000 of improvements and development at the Skyline Landfill.  We supported Waste Management with coordinating bids, selection of the contractors and awarding contracts.  During construction we coordinated with the TCEQ, Waste Management, and the contractors .  In addition, we reviewed submittals, issued change orders, resolved conflicts during construction, prepared the final construction reports, and administered the construction contracts.

Landfill Gas Services
Biggs and Mathews has provided landfill gas design/construction management services at the Skyline Landfill since 2013.  This includes life of site GCCS design and budgeting, design and permitting of GCCS expansions, bidding assistance, construction management, survey, and CQA services during GCCS installations, and preparation of record drawings at the conclusion of each project.  In addition, Biggs and Mathews also assists Waste Management with NSPS compliance, GCCS troubleshooting, and LFG remediation services as necessary at the site.

Drone Services
Biggs and Mathews has collected drone aerial topography data at the Skyline Landfill for the purpose of estimating airspace consumption and waste settlement rates.