ABOUT AQUIFER PROTECTION
The Lower Portneuf River Valley aquifer supplies the
cities of Pocatello and Chubbuck with their sole source of
drinking water. It is a relatively small aquifer located directly beneath these cities and
is protected from the impacts of urban and suburban development primarily by the thin
soils that lie above it. It has yielded very large quantities of low-cost water in the
past, but is being increasingly affected by contamination and is in need of special
protection to ensure a supply of affordable water in future.
The biggest water problems the lower Portneuf Valley
faces in the future are from:
1) Insufficient
capacity to meet demand.
2) Degradation of water
quality.
Examples of the land-use activities that have been identified to be of greatest concern
and that have had identifiable impacts on the lower Portneuf Valley's groundwater include:
1) Septic sewage.
2) Storm water and road runoff,
which is currently not regulated, and causes chloride and other forms of contamination.
3) The handling and storage of hazardous materials, including fuels.
4) The practice of constructing floor drains to accept waste water in commercial
facilities such as machine shops and service stations, which is currently is neither
effectively regulated or inspected/enforced.
The threats which these classes of activities pose to lower Portneuf Valley groundwater
are of two types:
1) The sudden appearance of contamination originating from a drain well, gravel pit or
other 'point' source, which can shut down public supply wells on short notice.
2) A gradual deterioration of water quality, eventually making expensive water
treatment measures necessary.
In either case, the result is costly remediation of the problem, to provide
safe drinking water. The costs of addressing such problems in the past decade have been
exceedingly high, and the familiar adage that "it is always cheaper to prevent ground
water pollution than to clean it up" has real relevance in this valley. An
informal compilation, constructed with the assistance of Pocatello, Chubbuck, and U.S.
Environmental Protection Agency officials,
documents the major costs incurred in remediating groundwater and soil contamination in
the lower Portneuf Valley over the decade 1990-00. In comparison, costs associated with
developing an understanding of aquifer dynamics, assembling existing information for
planning purposes, and identifying possible future approaches to ground water protection
are very small.
There are many types of approaches that can be taken to
protect a ground water resource. The EPA created a compendium of protection measures which
various communities have adopted around the country. They fall into various categories
such as Regulatory (e.g. zoning, subdivision controls, health-related restrictions),
Non-regulatory (e.g. land acquisition, voluntary restrictions), and Legislative (e.g. wellhead protection areas, special management areas
such as a Sensitive Resource
designation).
The EPA compendium has been examined by the Portneuf
Ground Water Forum and winnowed to a list of potentially applicable types of management
tools which could be adopted in the lower Portneuf Valley to enhance ground water
protection. A preliminary list of such approaches will be recommended to local government
as part of an EPA-funded effort to document existing information and provide guidance on
ground water protection.
To date, threats posed by other activities such as
gravel mining have been dealt with on a case-by-case basis, and have been resolved through
the open exchange of information and cooperative development of management plans (as an
example example, see the minutes
of the Highway Pond Working Group meeting, June, 1999). It is hoped that special cases
can be dealt with in future using the Highway
Pond consensus approach as a template.
However, regardless of how protective methods are
justified or which specific methods are proposed, none will achieve the goal of enhanced
ground water protection unless adopted, implemented, and enforced. One of the impediments
to adoption is that enhanced protection usually imposes stricter controls on land use.
Also, since aquifers tend to cross political and jurisdictional boundaries, multi-agency
cooperation must be secured prior to determining what protective measures and regulatory
approaches must be considered.
Achieving protection for an underground water supply is
a difficult and time-consuming process. Many people must become involved in, and assume
responsibility for, becoming aware of their water supply situation, evaluating the need to
protect it, and then making the decisions as to how to protect it. |
