Navajo Nation EPA-Public Water Systems Supervision Program

Environmental Planning Using GIS

The PWSSP is preparing to implement a Geographic Information System (GIS) program. A GIS
combines layers of information about a place to give a better understanding of that location.
Planning support systems can measure and compare performances of different planning
scenarios according to planner- or citizen-defined indicators for land use, transportation,
natural resources, and employment, to name a few. As communities grow, concerns over the
placement of gas stations, placement of sewer lagoons as opposed to septic tanks, placement
of hospitals, mortuaries, industrial buildings all need to be considered.

The PWSSP encourages all Navajo Nation community planners to become involve in
environmental planning in their community development initiatives. Protection of the community’
s drinking water source(s) is very important as it will have serious impact on the community.

Source Water Protection Guidance

The Navajo Nation faces significant challenges conserving our surface water supplies due to our arid southwest climate. Therefore, 97% of our source water
comes from groundwater. Groundwater is also used for raising livestock, agriculture, and industry. Groundwater was once thought to be protected by layers of
rock and soil, it is now known that groundwater can be vulnerable to potential contamination. To address this, the NNEPA-PWSSP has established a guide for
development in and around water supply watersheds aimed at protecting the local source waters from existing land uses and new developments; "Source
Water / Wellhead Protection Guidance document."

Navajo Nation Chapter agencies can use these Guidelines as part of the development review, comment, and approval process. Land developers can use the
Guidelines when designing projects located in the areas where water supply could be affected within watersheds. The Guidelines build upon existing land
use. They establish water quality control measures, specific to drinking water sources, for construction and new development, and also include
recommendations for long-term maintenance of the control measures. Overall, it serves as a road map for sensible development, increases the reliability of
the water supply, and reduces the potential for drinking water treatment costs.

Glen Canyon Dam
It began filling in 1963 following the completion of a
dam across the Colorado River near the south end of
Glen Canyon, and was not completely full until 1980.

Components of Susceptibility Assessments

Components of Susceptibility Assessment are used to develop the source water
protection plans. The SA process includes:

Identify the drinking water source (aquifer)
Identify the sources of potential contamination
Assessing how susceptible the drinking water source is to contamination
Making the Susceptibility Assessments available to the public

The SAs have been a process of gathering information and processing this data to
learn about the community's drinking water source. The information should tell the
residents where their water supply comes from and what conditions and/or
practices may pose threats to quality. CLICK HERE to view the Susceptibility
Assessment Survey Form.

Wellhead Protection Guidance Document

Protecting drinking water sources is the first line of defense in ensuring safe drinking water.