TEXTILES.ORG
Closing the A&L Salvage Landfill
By Kevin Harshberger, Ron Zitek, and Chris Eichelberger
Introduction
Description of the A&L Salvage Landfill site in rural northeastern Ohio:
- 400-acre site near Lisbon, Ohio, began operations in 2001.
- a C&D (construction and demolition) landfill with asbestos and “unrecognizable” waste—unauthorized municipal solid waste (MSW).
- 46 acres of waste with no cover.
- leachate seeps.
- strong H2S (hydrogen sulfide) odor.
- a fire! (aka—a “heating event”).
This site was a former surface coal mine. Most on-site soils were minespoil (a mixture of large rocks and soil). The cover was poor or nonexistent, mainly rocky material. Surface water and air intrusions were high. There were erosion scars and leachate outbreaks on slopes.
The site opened in 2001, but by 2005 the Ohio EPA (Environmental Protection Agency) got involved and findings and orders (F&O) were issued. The F&O established a $3.7 million closure bond and a $400,000 post-closure bond.
The landfill continued to operate from 2005 to 2009, but odors worsened and the U.S. EPA moved in. The U.S. Agency for Toxic Substances and Disease Registry (ATSDR) established an air-monitoring program.
Data gathered between 2008 and 2010 recorded hydrogen sulfide readings as high as 110 parts per billion (ppb). On-site H2S concentrations were as high as 2,400 ppb. According to ATSDR data from 2006, “exposure to levels [even less than] 100 ppb have been associated with headaches, vomiting, breathing problems, depression, and other symptoms.”
The site stopped accepting waste in February 2009, but there was no action toward closure—the owner(s) had disappeared!
By early 2010, the A&L site was an inactive, but unclosed, landfill with many violations, an intense odor, and a suspected underground fire. The problems at the site called for emergency action, and the OEPA was prepared because of a landmark program it had created just a year earlier.
CLOSER
Moving toward closure
The financial assurance money could be obtained by the state of Ohio, but the question was how it could be spent.
The OEPA is not an environmental contracting agency. With state procurement obstacles (public notice, low bid, wage rates, etc.), how could the OEPA actually do the work?
Using its new CLOSER—Closed Landfills and Orphaned Site Evaluation and Rating—program, established in 2008, the OEPA made the unusual decision to “self-perform” the work.
Unique contracting mechanism
The CLOSER program shortened the time frame at A&L:
- pre-bid meeting for A&L held March 29, 2010.
- design/build proposals submitted April 26, 2010.
- on-site kickoff meeting May 25, 2010.
The project progressed from pre-bid to the start of field work in eight weeks, with no design. Field work was completed in five months.
Compare to conventional time frame
A traditional time frame to establish a contracting mechanism could include:
- 3-6 months to solicit proposals for design.
- 6-9 months for design (including OEPA review).
- possible public hearings.
- 2-3 months for advertisement of construction.
- 2-4 weeks to contract and mobilize.
- a total of 12-19 months before on-site work could start—meaning no work in 2010, maybe not even 2011.
Construction issues
- Phase 1A—Handle the “hot spot”
- Phase 1B—Preliminary cap design (simultaneous with Phase 1A)
- Phase 2—Prepare subgrade (while cap design elements are finalized)
- Phase 3—Construct geosynthetic barrier and protective cover simultaneously
- Phase 4—Restoration
‘Heat event’
A subsurface fire had to be addressed:
- 23 geoprobes installed.
- temperatures in many probes above 140 F (170 F +/-).
- used 12in.-thick recompacted clay barrier to limit air intrusion.
- 7 geoprobes left in place for future monitoring.
Subgrade issues
- Rocky subgrade, virtually no soil
- Exposed piles of ACM (asbestos-containing materials)
- Top of landfill very flat
- No defined benches
- No defined benches
Excavating the exposed piles of asbestos-containing materials in preparation for smoothing the subgrade. Image courtesy of R.B. Jergens Contractors.
Dozers, trucks prep the subgrade to construct benches for slope stability. Image courtesy of R.B. Jergens Contractors.
Dozers, trucks prep the subgrade to construct benches for slope stability. Image courtesy of R.B. Jergens Contractors.
Subgrade prep for the geosynthetics layers. Image courtesy of R.B. Jergens Contractors.
Subgrade prep
- Excavated exposed ACM and moved it to top of landfill
- Dozers, compactors, and smooth drum rollers smoothed the subgrade (no need to add soil)
- Constructed benches for slope stability
- All work done as a lump sum, minimizing owner’s risk
Benefits of regulatory-led design/build
- OEPA’s geotechnical engineer identified potential slope stability issues.
- OEPA worked side by side with contracting, engineering, consulting, and installation teams.
- Several iterations of the bench configuration were discussed before a final design was determined.
- Slopes remained stable during and following construction.
Gas and odor control
- A geocomposite layer was installed under the cap to provide a collection mechanism.
- Composite was strategically placed to control costs.
- A collection trench was provided at the top of the hill.
- Installed 4-in. HDPE (high-density polyethylene) connections above grade to allow installation of passive solar flares.
- At OEPA’s suggestion, installed additional 4-in. HDPE connections spaced at 1/acre.
The “gas venting layer” of geocomposite material was installed beneath the 40-mil LLDPE textured geomembrane. The geocomposite gas venting layer was installed using a 15ft-wide roll of material on the subgrade, with a spacing of approximately 70ft between panels. The geocomposite material was installed directly prior to installation of the geomembrane, because strong winds could have displaced the geocomposite strips. Photo courtesy of AEG.
Installation of the 40-mil LLDPE textured geomembrane over the approved subgrade layer. The geomembrane was deployed in a downhill direction and ballasted with sandbags to prevent wind uplift. Panels are positioned to ensure proper seam overlap and then fusion welded as the membrane is deployed across the project. A pipe boot was later installed to seal the penetration from the HDPE pipe penetration. Photo courtesy of AEG.
A section of installed geomembrane on the A & L project. This photo displays the various grade changes and angles for the project. In general, geomembrane seams should be constructed parallel with the slope. This requirement creates the need to install the geomembrane from different setup points and requires additional seaming. Photo courtesy of AEG.
Geosynthetics facts
- Gas geocomposite—453,115sf
- 40-mil LLDPE (linear low-density polyethylene)—2,029,914sf (46.6 acres)
- Drainage geocomposite—2,029,914sf
- Subgrade prepped just ahead of installation crews
- All geosynthetic work was done in seven weeks (3 acres/day)
“The Ohio EPA utilized this site’s financial assurance and a design-build contract to speed forth on closure, the exemplary success of which may provide a template for future closure responses. AEG—an Approved Installation Contractor (AIC) as recognized by the International Association of Geosynthetic Installers (IAGI)—was proud to be part of this first-of-its-kind collaboration among regulators, designers, and contractors.”
–Chris Eichelberger
Conclusions
Summary of work
- Clay for “hot spot”—17,337cy
- Subgrade prep—120,000cy (+/-)
- Geosynthetics—4,512,943sf (103.6 acres)
- Protective cover soil—138,637cy
- Riprap channels—5,563lf
- Seeding and mulching—90.3 acres all in five months, with no design ahead of time!
Lessons learned
How was the A&L Salvage Landfill closed in just five months, two weeks ahead of schedule?
- Hands-on, directed efforts of regulators—the regulators were large stakeholders. They took on the role of “owner.”
- Key contractor relationships and “transparency”—the OEPA saw one entity, not three.
- Design/build team not only had proven individual experience, but also experience with each other.
- Entire team put high focus on communication.