Building on a Landfill

1. Building on a Landfill Celeste Manolas, Project Manager Santa Barbara County General Services Capital Projects

2. Project Overview • 6,000SF metal building • Intended for storage of County records • No occupancy • Adjacent to an existing metal storage building • Located at the Calle Real Maintenance Campus, atop the abandoned “Foothill Landfill”

3. Why?

4. Why would Santa Barbara County Choose to Build a Storage Building on a Landfill? • Requirements for constructing new buildings in Santa Barbara are too lax, we needed a REAL challenge? • We wanted to see if we could break the world record for the most expensive Butler building ever constructed? • Because it makes good planning sense

5. Calle Real Campus

6. Smart Growth and Sustainability • Infill; utilizes existing infrastructure • Reserves “buildable & occupiable” sites for future needs • Constructed of recycled materials, recyclable as well

8. About midway through design, Concerns were raised over siting the building over the abandoned landfill Something about methane…………….

9. Process • CEQA • Budget, schedule, scope impacted • Neighbors • Re-assessing options

10. (e) Construction of structural improvements on top of landfilled areas during the postclosure period shall meet the following conditions: (1) automatic methane gas sensors, designed to trigger an audible alarm when methane concentrations are detected, shall be installed in all buildings; (2) enclosed basement construction is prohibited; (3) buildings shall be constructed to mitigate the effects of gas accumulation, which may include an active gas collection or passive vent systems; (4) buildings and utilities shall be constructed to mitigate the effects of differential settlement. All utility connections shall be designed with flexible connections and utility collars; (5) utilities shall not be installed in or below any low permeability layer of final cover; (6) pilings shall not be installed in or through any bottom liner unless approved by the RWQCB; (7) if pilings are installed in or through the low permeability layer of final cover, then the low permeability layer must be replaced or repaired; and (8) periodic methane gas monitoring shall be conducted inside all buildings and underground utilities in accordance with section 20933 of Article 6, of Subchapter 4 of this Chapter.

11. Site Options?

12. (g) All on site construction within 1,000 feet of the boundary of any disposal area shall be designed and constructed in accordance with the following, or in accordance with an equivalent design which will prevent gas migration into the building, unless an exemption has been issued: (1) a geomembrane or equivalent system with low permeability to landfill gas shall be installed between the concrete floor slab of the building and subgrade; (2) a permeable layer of open graded material of clean aggregate with a minimum thickness of 12 inches shall be installed between the geomembrane and the subgrade or slab; (3) a geotextile filter shall be utilized to prevent the introduction of fines into the permeable layer; (4) perforated venting pipes shall be installed within the permeable layer, and shall be designed to operate without clogging; (5) the venting pipe shall be constructed with the ability to be connected to an induced draft exhaust system; (6) automatic methane gas sensors shall be installed within the permeable gas layer, and inside the building to trigger an audible alarm when methane gas concentrations are detected; and (7) periodic methane gas monitoring shall be conducted inside all buildings and underground utilities in accordance with Article 6, of Subchapter 4 of this chapter (section 20920 et seq.).Note: Authority cited:Sections 40502 and 43020, Public Resources Code; and Section 66796.22(d), Government Code. Reference: Sections 43021, 43103 and 44105, Public Resources Code; and Section 66796.22(d), Government Code.

13. Calle Real Campus

14. ENVIRONMENTAL CONSULTANT’S WARNING: would like to mention that their involvement in this project in no way constitutes an endorsement of placing human beings in buildings atop landfills. That being said, our project was viewed as an acceptable solution, but they made me promise not to plan any more buildings on the abandoned County landfill.

15. Community Outrage Community Outreach

17. FLOOR PLAN

18. FOUNDATION

19. METHANE MITIGATION

20. Methane Monitoring System

21. Methane Monitoring System

24. Health & Safety

26. Lessons Learned • Appropriate for limited applications • Select an environmental consultant with proven track record • Plan early, gain “buy-in” • Issues beyond construction

27. Lessons Learned • Involve landfill operator, you will need them to negotiate with LEA and CIWMB • Factor in cost and schedule contingencies

28. Pros and Cons • Reserves “occupiable” sites for staffed buildings • Metal building construction faster than typical construction • Pre-engineered building itself can be procured directly and fast-tracked

29. Pros and Cons Added costs Additional consulting Schedule impacts Methane monitoring and seismic unknowns Client frustration with process and increased budget

30. Building on a Landfill Celeste Manolas, Project Manager Santa Barbara County GS Capital projects cmanolas@co.santa-barbara.ca.us Special thanks to our consultants: