Memorandum

Subject: 	SDWA Section 1412(b)(8) Criteria

From:		Jennifer McLain 

To:		Docket for the Ground Water Rule

Date:		October 11, 2006

Section 1412(b)(8) of the 1996 Amendments to the Safe Drinking Water Act
(SDWA) requires the Administrator, when promulgating national primary
drinking water regulations “requiring disinfection as a treatment
technique for all public water systems, including  surface water systems
and, as necessary, ground water systems,” to promulgate as part of
those regulations “criteria that the Administrator, or a State that
has primary enforcement responsibility under section 1413, shall apply
to determine whether disinfection shall be required as a treatment
technique for any public water system served by ground water.” EPA has
discharged this obligation in the final Ground Water Rule (GWR).  

The (b)(8) criteria are expressed in the GWR in two parts.  The first
part consists of the portions of the GWR used to identify ground water
systems susceptible to fecal contamination:  

Regular ground water system sanitary surveys to check for significant
deficiencies in eight key operational areas; 

Triggered ground water source monitoring to detect fecal contamination
at ground water systems (GWSs) that do not provide 4-log treatment of
viruses and have a Total Coliform Rule sample that tests positive for
total coliform; and

Optional source water assessment monitoring to give States the ability
to target additional source water monitoring to systems that are more
susceptible to contamination.  

This rule requires a GWS to comply with the rule’s corrective action
requirements if a significant deficiency is identified during a sanitary
survey.  Also, the rule requires a GWS to comply with the corrective
action requirements if one of the five repeat ground water source
samples (or, at State discretion, the initial source sample or the
assessment source water monitoring sample) has tested positive for fecal
contamination. 

   

The second part consists of provisions in the final GWR that are
designed to help systems and States determine when disinfection is
necessary.  GWSs, following consultation with their State, must
implement one or more of the following corrective action options: 

Correct all significant deficiencies; 

Provide an alternate source of water; 

Eliminate the source of contamination; or 

Provide treatment which reliably achieves at least 99.99 percent (4-log)
treatment of viruses (using inactivation through disinfection, removal,
or a State-approved combination of 4-log virus inactivation and removal)
for each ground water source.  

Each of these corrective actions is intended to remove all or nearly all
fecal contamination, including both viral and bacterial pathogens.  This
array of corrective actions reflects EPA’s judgment that disinfection
is not necessary if another form of corrective action achieves the
desired result. 

Section 1412(b)(8) also requires the Administrator, simultaneously with
promulgating the GWR, to promulgate a rule specifying “criteria that
will be used by the Administrator (or delegated State authorities) to
grant variances from this [disinfection] requirement according to the
provisions of sections 1415(a)(1)(B) and 1415(a)(3).”   Section
1415(a)(1)(B) authorizes States with primary enforcement responsibility
for public water systems to grant variances from any NPDWR that
“requires the use of a specified treatment technique with respect to a
contaminant,” if the system can demonstrate to the State’s
satisfaction that “such treatment technique is not necessary to
protect the health of persons because of the nature of the raw water
source of such system.”  Section 1415(a)(3), in turn, authorizes the
Administrator to grant a variance from a treatment technique requirement
of a NPDWR upon a showing that an alternative treatment technique not
included in that regulation is at least as efficient in lowering the
level of the contaminant of concern.

EPA has already promulgated regulations at 40 CFR Part 142, Subpart E,
specifying criteria for the States’ and the Administrator’s use in
granting variances under sections 1415(a)(1)(B) and (a)(3).  Nothing in
the GWR warranted a change to those criteria.  Therefore, to the extent
that variances under those statutory sections are relevant to public
water systems subject to the GWR, those criteria would apply.

EPA does not believe that the first variance provision is applicable to
GWSs under this rule.  EPA notes that the structure of the GWR obviates
the need for variances under section 1415(a)(1)(B).  As discussed above,
the regulation employs a targeted approach for its treatment technique
requirements and, indeed, establishes a regime whereby corrective action
is required only for those systems that have the most risk, as indicated
by sanitary surveys or triggered ground water source monitoring.  The
treatment technique requirements account for the nature of the PWS raw
water source because GWSs are required to implement a corrective action
when triggered source water monitoring identifies fecal contamination in
the source water.  States may also require corrective actions in
response to results from optional State-required assessment monitoring.

 

With respect to the variances authorized under 1415(a)(3), EPA notes
that when a corrective action is required, the State has a choice among
several authorized options.  In each case, the State is free not only to
choose among those options, but also to choose how to accomplish the
particular corrective action it has selected.  For example, even where
treatment may be needed, the GWR does not require disinfection, but
authorizes States to approve alternative technologies (e.g., membrane
filtration) that ground water systems may use alone or in combination
with other approved technologies to achieve the desired level of
pathogen removal.  If the State does not immediately prescribe a
corrective action, the ground water system will have 30 days to consult
with the State on an appropriate action.  During this time, the ground
water system would be able to discuss any alternative treatment that
would meet Section 1415(a)(3).  Given the broad range of corrective
action treatment technique options available in the rule, it is unlikely
that a system could demonstrate to EPA that an alternative treatment
technique not included in that regulation is at least as efficient in
lowering the level of the contaminant of concern.  

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