Geologic, Hydrologic, and Urban Hazards for Design in Desert Environments - Design with the Desert: Conservation and Sustainable Development - page 104

plants, increases instead of infiltrating into the soil. In this case, the human activity caused
an alteration in the flow of water in the watershed, and the increased flooding was the result .
How can one differentiate between a natural hazard or a human caused hazard? Take,
for instance, a scenario where a high level of arsenic found in a municipal water well.
Differentiating this as the result of anthropogenic activities or a natural concentration can
be difficult and will require a formal investigation and the involvement of experts to deter-
mine the source of this unwanted constituent, and the necessary studies could take years
and thousands of dollars to complete. In the remainder of this chapter, we discuss the
impacts of anthropogenic activities in land use and development that can have significant
impact in Southwestern deserts.
Hazards caused by human activities in the built environment generate concerns that
can lead to adverse impacts on human health, contamination of air, water or land, or cause
the loss of property use or value from this activity. Numerous hazards result from the
construction and maintenance of urban environments, and we discuss some of those that
are related to pollution of land and water and address some hazards that are relatively
well-defined spatially and can either be mitigated or avoided by effective management or
planning.*
Pollution-related impacts generally involve two- or three-phase media as combinations
of air, water, and soils. Every operation that produces any kind of waste in desert envi-
ronments has the potential for releasing pollutants that can contaminate these resources.
Although mining is perhaps the largest source of pollution in the southwestern United
States, other sources of pollution with lasting impacts include manufacturing, military
bases (particularly Air Force facilities), retail, auto shops, drycleaners, laboratories, and
fueling stations. Most of the information in this section is derived from websites that are
regularly updated, providing users with up-to-date information on urban hazard issues,
and several excellent summary volumes also are available. 46-48
5.7.1 Regulatory Environment
The United States has a multitiered level of oversight and enforcement of environmental
regulations related to hazards that can or may impact the public. On the federal level, the
U.S. government has designated the Environmental Protection Agency (EPA) † as the prin-
cipal agency to oversee concerns about environmental contamination or hazards to human
health. The EPA has broad powers to enforce federal laws on environmental protection
and bring regulated activities in compliance with national standards. Each state has their
own department of environmental quality or compliance that sets statewide guidelines
for compliance with EPA for health or contamination standards. Detailed information can
be obtained on environmental regulations from each state's department of environmental
quality websites. ‡ The county government is given authority to regulate some aspects of
environmental quality, such as air quality monitoring and dust control or other respon-
sibilities delegated by the State or created by environmental policy. On the local level,
municipal governments have the responsibility to set land-use guidelines through zon-
ing laws and regulate local land uses and manage municipal solid waste and wastewater
operations. Together, these public agencies comprise the police power of enforcement of
* For a comprehensive overview of environmental land management see Raldolph. 45
† http://www.epa.gov/ (accessed June 23, 2011).
‡ For Arizona, http://www.adeq.gov; for Nevada, http://www.ndep.nv.gov; for California, http://www.
calepa.ca.gov/, for New Mexico, http://www.nmenv.state.nm.us/; for Texas, http://www.tceq.state.tx.us/ (all
accessed June 25, 2010).