Good evening everyone, and thank you for coming. My name is Chris - PDF document

• Good evening everyone, and thank you for coming. • My name is Chris Corliss and I am the Manager of the Louis Berger’s Solid Waste Services Group. We are working on behalf of the New Jersey Department of Environmental Protection on the Fenimore Landfill Closure Design. • Tonight, I will be speaking to you about the Fenimore Landfill Closure. 1

• I’m going to divide my talk into 3 parts. • First I will talk about the purpose of properly closing a landfill, and what comprises a landfill closure. • Next, I will give an overview of the various project phases. • Finally, I will discuss the schedule of future activities. 2

• The site was operated as a private sanitary landfill from the mid ‐ 1950s to approximately 1979. During its operation, municipal solid waste was accepted at the landfill. • However, the landfill was not properly closed. • The overall goal of a landfill closure is to protect human health & the environment. • The main objective is to dry out the waste and diminish hydrogen sulfide production & migration. • In general, the Fenimore Landfill gases need to be collected & treated, while keeping water from infiltrating into the landfill. 3

• There are Federal (40 CFR 258.60) and State (N.J.A.C. 7:26 ‐ 2A) Regulations that govern landfill closure. • In general, landfill closure involves providing engineered measures to minimize rainwater infiltration & gas production / migration. • In addition, the closure components need to include a stormwater drainage system that manages runoff & controls soil erosion, while providing systems for gas management, treatment & monitoring. 4

The Fenimore closure work can be broken into three phases. • The first two phases are associated with the landfill closure • The third phase deals with the site after it is properly closed. • Phase I will involve the gas wells and associated piping installation. • Phase II will consist of the liner & capping installation • The third phase will handle long term gas treatment & monitoring. • 5

• This landfill closure addresses the area associated with the fill material that was brought on site by SEP. • The grey area depicted on the aerial image represents the location where the fill material was deposited. • This area is approximately 19 acres. • One of the closure goals is to minimize additional disturbance beyond the fill material area. • The yellow line represents the Limit of Disturbance associated with Phase II’s liner & capping. • The total closure area limit of disturbance will be 22 acres. • The primary reasons for the disturbance increase is due to site grading and stormwater management system needs. 6

• Upon taking control of the site, the NJDEP installed temporary stormwater controls and applied Posi ‐ Shell in the fill material area. The Posi Shell cover is a spray ‐ applied coating. Its purpose is to reduce water infiltration, improve odor control, and aid as an erosion control measure. In addition, the Posi Shell changes color in areas with pronounced hydrogen sulfide levels that migrate to the ground surface. • The NJDEP installed nine Gas Extraction Points (GEP) as an interim emergency measure in locations where the Posi Shell had indicated a hydrogen sulfide presence. • These GEPs were connected to collection piping and a treatment system, which is currently operational. • The image on this slide depicts the locations of the nine GEPs, the gas collection piping (as depicted by the magenta line) and gas treatment system (located at the bottom left corner of the image). • The dashed line represented on this image and subsequent Phase I slides represents the approximate extent of the fill material area for reference purposes. 7

• As a part of the Phase I Closure, an additional 21 wells will be installed to collect and monitor hydrogen sulfide at each location. • The wells will be installed at varying depths extending between approximately 10 feet to 30 feet below existing ground surface. • There will be valves and ports at each well to monitor and adjust the gas collection. • This will enable targeted gas collection locations, as needed during system operation. 8

• The well locations were selected to supplement and fill existing GEP coverage gaps. • The purple line represents an estimated 125 foot subsurface Radius of Influence (ROI) once a vacuum is applied to the gas well. • Once the system is operational, there will be a constant vacuum on the landfill, and this system will be operational during the Phase II capping and liner installation. • As shown on this slide, there is an overlap in well vacuum influence to provide for complete collection coverage. 9

• Once the wells are installed, they will be connected to a trenched collection piping network (shown in blue). • In general, the collection piping will be a looped system with an additional header pipe that splits the loop. • There will be valves installed on the collection pipe in key locations to enable operation flexibility. • The collection piping network will be connected to the treatment equipment depicted in the bottom left corner of this image. 10

• During the gas well and piping phase, a temporary liner (green) will be installed on portions of the existing sideslopes. • These sideslope areas have demonstrated a higher hydrogen sulfide presence. • The liner will function as a “blanket” in these areas to prevent hydrogen sulfide migration and enable the gas wells to better collect hydrogen sulfide. 11

• The prior slides provided an isolated view of each gas collection system feature. This slide ties together those isolated features into one overall image. 12

• I will now be discussing Phase II (liner & capping) • The existing topography will need to be adjusted to provide for proper closure grades and storm water management. • One of the grading goals is to minimize disturbing the fill material. • The table on the left side of the slide shows colors that represent where topography needs to be raised or lowered to achieve grades prior to installation of the liner. • In general, a majority of the landfill top areas will require minimal grading. • There will be stormwater management swales on the top of the landfill that will require minor grading work. • In order to achieve grades, onsite old fill will be used that is located beyond the fill material area (which is represented by the dashed line). • The net balance of material needed to achieve grades prior to the liner will be approximately 9,000 Cubic Yards (CY). 13

• This slide depicts the cap cross section that will be installed. I will discuss each layer of cap from the bottom up. • The grading that I just spoke about is the regraded subgrade and is the base of the cap. The materials associated with the regrading work is a combination of waste & imported fill. This layer provides grade control and smooth surface, as well as provides adequate bearing capacity for overlying layers. • The first cap layer is a 6” liner bedding soil, followed by a geomembrane liner. This liner is a barrier to control gas emissions and water infiltration. • The Geocomposite Drainage Net allows water that infiltrates into the soil to be collected and managed. • The 12” imported clean soil and 6” topsoil will enable the establishment and growth of a final grass cover. 14

• There will be a need to import clean material to achieve proper landfill closure. • The top table depicts the required volumes associated with the various landfill cap components I just discussed, as well as an approximate magnitude of loaded trucks that will bring material to the site. • The bottom table depicts an approximate range of daily loaded truck trips within the general timeframes indicated. • It is anticipated there will be an initial larger quantity of trucks this summer. • The quantity of trucks is anticipated to decrease this fall • There should be a small quantity of trucks during the winter months. • Next spring, it is expected that there will be an increase of trucks for an approximate two month period to finish the closure work. 15

• The image on the slide depicts the limit of disturbance (yellow) and the proposed site grading (blue) that are overlaid on an aerial image. • The portions of the landfill’s top will be slightly re ‐ graded to provide proper stormwater drainage. • The side slopes will be re ‐ graded to provide adequate slope stability and proper stormwater drainage. 16

• I will be discussing stormwater swales and downchutes in the upcoming slides. The following photographs are intended to provide an example of each. The grass lined swale will have a matting to prevent erosion. The gabions are rock filled wire baskets. • These components will be above the geomembrane liner. 17

• This slide depicts the locations of the proposed grass lined swales with reinforcement matting on the top of the waste mound (shown in green). • These swales will be grassed to provide a natural meadow ‐ like condition upon closure completion. • The intent of these swales is to collect and convey stormwater water from the top of the landfill to reduce water infiltration into the waste. 18