Whitehead E. S. routinely works with buyers/sellers of commercial real estate on a full range of environmental concerns. In Dallas, this includes building structures on closed landfills. In many cases, the former landfill was an unknown that was identified or suspected in the Phase I Environmental Site Assessment (ESA). This is especially the case along IH-35 in Dallas moving north to Lewisville where much of the area was formerly used for sand and gravel mining. The former pits were filled in over the years with a mix of earthen fill, concrete, bricks, asphalt, and in some cases municipal solid waste (MSW) such as trash (paper), food waste, landscape debris, glass, wood, etc. Most of these landfills predate regulations from the U. S. Environmental Protection Agency (EPA) and the Texas Commission on Environmental Quality (TCEQ) and most had little to no design features of properly designed landfills.
Decomposition of the waste generates landfill gases such as methane and carbon dioxide along with lesser quantities of butane, ethane, propane, hydrogen sulfide, and even volatile organic compounds (VOCs). A primary concern to the state and TCEQ is the accumulation of potentially explosive methane in building structures located on top of these landfills.
Properties with building structures on closed landfills are covered by 30 Texas Administrative Code (TAC) §330.954 Subchapter T. The purpose of the Subchapter T rules and regulations is to ensure that potentially explosive gases are appropriately monitored and/or abated to protect occupants in these buildings. Subchapter T rules apply to all developments over closed landfills except for single-family or double family homes which are not part of a residential subdivision.
A key issue with the Subchapter T rules and regulations is whether you need a Permit with a public hearing or Registration using TCEQ forms. The level of effort and cost will vary significantly with the Permit versus the Registration. A Permit is required when the on-Site enclosed structure was constructed after September 1, 1993, while properties with older structures only need to register with the TCEQ.
If you have questions or need additional information to Permit or Not to Permit (Register) a property with a potential Subchapter T issue, contact Michael Whitehead. Ms. Iryna Kushnirsky (TCEQ Remediation) was gracious to send us a PowerPoint presentation from the MSW group, “Development Over a Closed Landfill” that is very helpful. If you would like the presentation contact Michael at email@example.com.