Methane Gas Problems in Lennar Homes

Below are two excerpts from reports commissioned by Lennar Corporation and delivered to Lennar Corporation. The full reports are full of startling details and numbers.

The saddest thing about this, is Lennar knew about it, but instead of doing the right thing, they put these homeowners through the ringer. Now the state and federal authorities are investigating, and three prominent law firms are looking at the reports.

Report to Lennar Corporation
Excerpt from Professional Services Industries, Inc.

The concentrations of methane exceed the lower explosive limit beneath the slab, and therefore pose a potential threat to the safety of the occupants within the buildings. The methane concentrations must be reduced to a level significantly below the lower explosive limit, and sufficiently low so as not to cause elevated methane levels within the interior of the homes. We suggest setting a target threshold for methane at less than 2% LEL. Soil gas venting methods vary depending on the site conditions and desired results. PSI will be happy to assist you in designing a venting system and monitoring program specific to the site needs. Any venting program will require periodic monitoring of the vented gas to verify that the concentrations are decreasing to the desired target level. At this time, it is not possible to determine the required duration for the monitoring period, but we estimate it to be between 6 months and 2 years for a passive venting system.

Excerpt from Trident Environmental Services, Inc.
Report to Lennar Corporation - This one is in bold, only because it was in bold in the report. Trident thought it was important enough to make sure Lennar didn't skip over it.

It is recommended and considered imperative that a combustible gas meter that measures in % Lower Explosive Limit be used to measure combustible gases around cracks and penetrations in the slab to determine if potentially flammable or explosive mixtures of methane exist in the residences. If levels of combustible ases significantly exceed 10 % of the LEL (5000 ppm) for methane at cracks and slab penetrations, it is recommended that the occupants of both residences be relocated until assessment and remedial actions can be completed by the soils engineering firm and entry of methane gas into both residences are controlled.