Current through Register No. 13, March 27, 2025
(a) If any
regulated contaminant is detected by the permittee's monitoring at a
concentration that exceeds the applicable AGQS, the permittee shall:
(1) Within 10 days of receiving the test
results that show the exceedance, notify the department of the
exceedance;
(2) Within 21 days of
receiving the test results that show the exceedance, test water for the
regulated contaminant that exceeds the AGQS from each private or public
drinking water supply well within 1,000 feet of the location where the
exceedance occurred;
(3) Report the
results of the testing required by (2), above, to the department within 45 days
of collecting the samples;
(4) For
exceedances of contaminants other than 1,4-dioxane, perfluorooctanoic acid,
perfluorooctane sulfonic acid, perfluorononanoic acid, or perfluorohexane
sulfonic acid, or any combination thereof, from a facility that discharges
treated wastewater to groundwater, prepare, submit, and implement a written
response plan in accordance with (b) through (g), below, to ensure that
groundwater quality criteria are not violated at the boundary of the
groundwater discharge zone; and
(5)
For exceedances of 1,4-dioxane, perfluorooctanoic acid, perfluorooctane
sulfonic acid, perfluorononanoic acid, or perfluorohexane sulfonic acid, or any
combination thereof, from a facility that discharges treated wastewater to
groundwater, proceed as specified in Env-Wq 402.251.
(b) If the testing done pursuant to (a)(2),
above, shows the presence of a regulated contaminant in a private or public
drinking water supply well at a concentration that exceeds the applicable AGQS
and the department determines that it is more likely than not that the
permitted wastewater discharge is the source of the regulated contaminant, the
permittee shall:
(1) Expand the testing of
public and private drinking water wells beyond 1,000 feet as necessary to
determine the extent of the exceedance of the applicable AGQS in drinking water
supplies;
(2) Within 21 days of
receiving the test results obtained pursuant to (1), above, submit a proposed
response plan to the department that evaluates the relative costs and benefits
of:
a.Installing treatment to remove the
contaminant from the water supplied from the well; or
b.Provide alternate water to those served by
the drinking water supply by:
1.Providing
bottled water as an interim mitigation measure until a long-term water supply
alternative is provided; and
2.Providing a long-term alternative water
supply by:
(i) Installing, testing, and
maintaining a point-of-entry water treatment system at each structure served;
or
(ii) Connecting each structure
served to a public water system.
(c) Subject to (d), below, the
response plan shall include the following:
(1) All actions necessitated by (b), above,
if applicable;
(2) Inspection and
audit of activities and procedures at the facility to determine possible
sources of groundwater contamination;
(3) Further site investigation to evaluate
additional potential sources of groundwater contamination and the extent of
their impact on groundwater quality;
(4) Modification of facility operation as
needed to eliminate the cause of the exceedance;
(5) Removal or containment of the source of
the groundwater contamination; and
(6) Groundwater quality
restoration.
(d) If
facility operations cannot be modified to eliminate the cause of the exceedance
or if the groundwater quality cannot be restored, the response plan shall
include a schedule of activities that will be implemented for facility
closure.
(e) The permittee shall:
(1) Submit the response plan to the
department within 60 days of receiving the test results that show the
exceedance; and
(2) Implement the
response plan within 30 days of department approval.
(f) Within 90 days of receiving a proposed
response plan, the department shall notify the permittee in writing of whether
it has approved the plan. If the department does not approve the plan, the
notice shall specify the reason(s) for the disapproval.
(g) The department shall approve the response
plan if the department determines that the plan, if implemented as specified,
is expected to:
(1) Remove, treat, or contain
the source(s) of groundwater contamination to prevent the additional release of
regulated contaminants to groundwater;
(2) Achieve compliance with AGQS;
(3) Ensure safe drinking water and otherwise
protect human health and the environment; and
(4) Contain and confine groundwater
contamination within the limits of the groundwater discharge zone, delineated
in accordance with Env-Wq 402.23(a).