What is the Ground Water
By Bruce Macler, U.S. EPA, Region 9, San Fransico
Under the Safe Drinking Water Act (SDWA), EPA is required to establish
disinfection requirements for groundwater systems. A system in this case
includes the source, well, treatment hardware and distribution lines. The
existing Total Coliform Rule (TCR) mandates monitoring for fecal contamination
in public water supplies, but does not explicitly require correction of
violations or other identified problems. Additionally, it only acts "after
the fact," since by the time TCR monitoring results have revealed
contamination, people have already consumed the contaminated water. Congress
asked EPA to ensure additional protection to the public to prevent such
situations. Currently, many states have some groundwater system protection
and/or disinfection regulations already in place, although the specific
requirements vary substantially. The GWDR will provide the national guidance
and requirements to correct problems and provide adequate protection.
Why the Public Health Concern?
There are legitimate concerns for public health from microbial
contamination of groundwater systems. Microorganisms and other evidence
of fecal contamination have been detected in a large number of wells tested,
even those wells that had been previously judged not vulnerable to such
contamination. The scientific community believes that microbial contamination
of groundwater is real and widespread. Public health impacts from this
contamination while not well quantified, appear to be large. Disease outbreaks
have occurred in many groundwater systems. Risk estimates suggest several
million illnesses each year. Additional research is underway to better
characterize the nature and magnitude of the public health problem.
Current Thinking on Regulatory Elements
The working public health goal for the GWDR is to protect consumers
from fecal contamination in their drinking water. To achieve this goal,
the final regulation should ensure adequate protection of sources, wells
and distribution systems from fecal contamination and provide treatment
if contamination occurs. In addition, it must be feasible to implement
and enforce. Options so far actively being considered center around a general
requirement for a periodic sanitary survey to include wells and treatment,
distribution, operations and management, and monitoring and assessment.
Correction of fecal contamination or system defects would be required,
which could include installation of treatment. Maintenance of a distribution
system disinfectant residual (for systems with distribution) has wide support.
A groundwater vulnerability assessment may be required. Highly vulnerable
sources would have additional source water monitoring requirements. Monitoring
requirements may focus on E.coli and coliphage as indicators of fecal contamination.
Operator training or certification will likely be required.
How Might Small Community Systems be Affected?
Groundwater-based public water supply systems are substantially
different from surface water systems. Also, groundwater systems have very
different circumstances with respect to each other and to the likely elements
of this rule. Compared to larger groundwater systems, the small community
systems (serving fewer than 1000 people) have fewer resources and less
routine oversight. Small non-community systems (schools, restaurants, etc)
typically have even more limited resources and infrastructure. Most have
no distribution system. The majority do not disinfect or treat their water
at all. Operators are generally not certified. These small systems have
the majority of microbial violations, mostly from source or wellhead contamination.
They are not well represented in the drinking water community. Because
of their resources and limited current involvement with drinking water
regulations, the GWDR would likely have the most noticeable impact on these
systems. New SDWA amendments direct EPA to specifically consider the feasibility
of regulatory requirements for small systems.
Current Workgroup Activities
There has been wide and open participation in the regulatory
discussions, including representatives from states, utilities, EPA, other
agencies and interest groups. Over the last two years, broad issues of
public health problems and goals, existing state protection approaches,
vulnerability assessment methods and general treatment possibilities have
been considered. As the workgroup discussions have developed, several topic
areas have been identified for detailed study. Information-gathering groups
are now examining the public health and microbiological monitoring issues,
existing state and federal regulations and approaches, criteria for sanitary
surveys, possible requirements for operations and maintenance, and appropriate
treatment technologies. It is expected that these groups will bring forward
their recommendations during 1996. EPA is anticipating a proposed GWDR
How Can You Get Involved?
The GWDR discussions are open to all. Interested parties are
encouraged to participate, especially members from small communities. If
you are interested or want more information on this rule, contact Bruce
Macler, GWDR Regulation Manager, at 415 744-1884 or firstname.lastname@example.org.