projects

Design-Build of Alternate Final Cover (ClosureTurf®)
Union Hill Church Road Landfill – Phase 3 Closure

Gordon, GA | 2016 – 2017

Scope of Services

Notable Accomplishments

Oasis Consulting Services was instrumental in acting as liaison with the Georgia Environmental Protection Division (GEPD) to obtain the first permit for a landfill cap utilizing ClosureTurf in the state.

Because of Oasis’s innovative design, the project was completed 3 months ahead of schedule and saved $1.5 million of SPLOST funds with minimal cost to maintain for the county.

This project was the 2018 ACEC Georgia Engineering Excellence Award Winner, Environmental Category

Project Gallery

Project summary

Oasis has been providing engineering consulting services for
the Baldwin County Board of Commissioners since 2015,
including semi-annual groundwater and surface water
monitoring, quarterly methane monitoring, and other remedial
and on-call tasks. In 2017 Oasis completed a $2.74 million
turnkey design-build contract for a 21.5-acre alternate final
closure system in the Phase 3 MSW disposal area for the
Baldwin County Board of Commissioners. The system uses the
patented ClosureTurf®, a synthetic engineered turf cover which
is durable and drastically reduces or eliminates the need for
typical costly landfill post-closure maintenance.

The ClosureTurf® final cover system also eliminates a costly prescriptive clay
layer as well as vertical landfill gas collection wells. Oasis worked closely
with the Georgia Environmental Protection Division (GAEPD) to achieve
approval for the first alternate final cover system of its kind for final
closure of a municipal solid waste (MSW) landfill in Georgia.
Oasis was awarded the 2018 American Council of Engineering Companies
of Georgia (ACEC Georgia) Engineering Excellence Award in the
Environmental Category for this project.

The Union Hill Church Road Landfill has nine completed cells and ceased accepting outside waste in 2007, at which time Baldwin County began a two-year permitting process with GAEPD to close the footprint for Phase 3. The closure design was approved in 2009 and included a standard Subtitle D cap with 18 inches of clay, a 40-millimeter liner, and 25 passive vertical gas wells which required 675 vertical feet of drilling. The initial cost estimate totaled $3 million for closure completion and included the initial post-closure. However, in 2009 the County was faced with a 14% unemployment rate, an overall community loss of 4,000 jobs, and a rapidly shrinking tax base. By the end of the year, SPLOST and LOST funds were 20% lower than initial projections and the landfill was unstaffed. In 2010 the County submitted a letter to the GAEPD District Office requesting a delay of closure until 2013 due to lack of funding.

Beyond the budgetary restrictions, the Landfill faced a number of compliance issues. In 2009, 2012, and 2013, the landfill received unfavorable inspections. Poor erodible soils led to site erosion problems, and the soil proved difficult to establish vegetation. Ultimately, any landscaping – such as grass or sod – would fail to take root and die,
leading to additional costs for what would be futile landscaping replacement efforts. By 2014 the County had entered into a Consent Order for the closure of Phase 3. Closure activities began the summer of 2015 and were scheduled for completion in September 2016, with permanent grass scheduled for installation April 2017. Because of the Consent Order, stipulated penalties were in place if these milestones were not met.

Oasis was retained in 2015 to provide overall design and management, certification, and closure documents for the Phase 3 closure. In addition, Oasis provided laboratory soils testing in our in-house soils lab; CQA services; and final certification and final closure documentation necessary to obtain a Closure Certificate for Phase 3. The construction started in August 2016 and was completed in February 2017.

Oasis worked closely with both Baldwin County and GAEPD to ensure compliance. Once the closure activities began, the County quickly realized that in addition to the out-of-date budget, they had a number of major issues which had not been taken into account when the initial plan was approved in 2009:

• They were restricted by poor soils for vegetation.
• Suitable clay at the site was limited.
• Waste removal would be extremely problematic due to well drilling.
• Leachate outbreak repairs were a potential problem.

Oasis’s innovative solution utilizing ClosureTurf®, which was a relatively new product, would address each of these problems. By providing an option for the use of Armorfill™ to enhance the turf sand infill, the need for diversion berms and downchutes was also eliminated; the entire cap would be able to sheet flow to Armorfill™ perimeter ditches.

Oasis recognized that using this unique alternative landfill cap system had the potential to mitigate poor soil conditions, eliminate well drilling for waste removal, and reduce short-term and long-term exposure to risk. As a result overall costs for the project would be reduced, saving the County money over time. Oasis prepared an alternate final cover system design and submitted the Minor Modification package to GAEPD, all while meeting the requirements of the Consent Order.

By using an alternative cap with engineered turf, Oasis was able to solve not only the problems caused by poor soil and erosion, but also to decrease the cost of maintenance requirements over time. This innovative solution further met the requirements of the Consent Order, both in terms of compliance and completion ahead of schedule.

Oasis helped Baldwin County overcome significant challenges including a limited budget, poor soil conditions, GAEPD permitting requirements, and strict scheduled milestones. Additional economic and sustainable benefits included lowering the overall risk and lessening the environmental impact by eliminating the use of pesticides or fertilizers (which would have been necessary for grass or sod). Costs were also saved by reducing the need for County labor for years to come.

The total project budgeted cost was $4.7 million. The Phase 3 closure was completed in January 2017 for $3.2 million – three months ahead of schedule and for $1.5 million under budget, resulting in taxpayer savings.