|The Houston area, and the Gulf Coast in general, is laced by numerous growth faults which are geological hazards that are known to impact and damage house slabs, building-support structures, highways and associated foundations. Water-supply wells and pipelines, oil and gas wells and pipelines, and other anthropogenic structures are also affected by growth faults, and have cost millions of dollars to repair over the years as a result of the small, but significant, movement of these faults. At depth, these faults have created economically important oil and gas reservoirs, sulfur and uranium deposits, and geopressured-geothermal energy. But they also provide pathways for dissolved uranium and radionuclides (e.g. 226 radium and 222 radon) and natural gas to migrate from great depths upward into Houston groundwater supplies in various areas within the Evangeline and overlying Chicot Aquifers. Such pathways also allow other hazardous substances from human activities to migrate vertically or from one water-bearing unit to another. Such faults impact the Houston environs as a subsurface geological hazard although their full significance has gone unrecognized for decades since the U.S. Geological Survey (U.S.G.S.) budgets for mapping the faults in the Houston area were eliminated in the late 1970s. Houston building foundation repair industry has since flourished in fault-prone areas unsuitable for construction without foundation design accommodations. This would require a more complete knowledge of fault locations throughout the Houston area. |
The authors have called for a new hazard alert system to be developed by the U.S.G.S. that is consistent and compatible with the County Flood Plain maps to warn builders and home buyers of the potential risks known in the Houston area regarding the presence of faults. Such a system could identify faults that exist under existing pipelines and other structures, and faults where natural hazardous substances are known to occur.