Throughout much of the "oil patch" water exemplifies the economic, sociologic, political, and ecologic lifeblood of the community. The permanent supply of usable water, on which the arid West depends for survival, faces many hazards. Currently, much available water exceeds or is rapidly approaching public health limits and the tolerance level of the inhabitants.

Although oil field operations contribute a small proportion to total degradation of the hydrologic system, each incident of oil field pollution is specific and highly newsworthy. When attempts are made to clean up waters, the oil industry provides the first and most vulnerable target. Oil field practices can and do pollute water, mainly by increasing total dissolved solids (principally chlorides and sulfates), but also by releasing crude oil.

Groundwater pollution commonly is difficult to prove and may not appear immediately. Conversely, its effects may persist for many years. Pollution may occur from several sources.

Evaporation pits:
Regardless of the concentration of brine entering a pit, the only substance leaving the pit by evaporation is pure distilled water vapor. Everything else remains behind forever or enters the water system either by seepage through the bottom of the pit or overflow. In Colorado during 1969, 27 million bbl of water (1,110-35,000 ppm salinity) went to unlined pits. A 1966 detailed study of a groundwater basin in northeast Colorado showed that one small brine pit contributed a 27-ppm/year salinity increase to the entire groundwater basin.

Insufficient surface casing:
Any surface casing which is not set below all freshwater aquifers constitutes a pollution hazard.

Any injection system:
Waste disposal or waterfloods constitute a hazard; not only from casing leaks but also from cross-formational flows through natural or induced fractures.

Abandoned wells:
Corroded casing and bad cement jobs afford opportunities for permanent cross-formational flow.

Oil spills:
Oil on pits or streams constitutes a hazard to wildlife. Last year, a check of 31 pits in Colorado showed 310 dead ducks. Oil-soaked dead ducks afford an inestimable publicity impact.

Seismic shotholes:
In many areas, these can provide a ready admixing of salt- and freshwater aquifers.

The solution is attainable, but not simple. It requires a constant awareness of the value of fresh water, the habitat of groundwater, and the pollution potential of each operation. Constant planning, monitoring, and policing of the operation will not only prevent pollution, but will improve the industry's image and save oil companies money.