A.
When
allowed. Unless the department determines that the nature or the volume
of additional wastewater will adversely affect existing water quality of the
receiving water, new sources of wastewater may be added to a sewer system
having a CSO discharge point if:
(1) The
licensee is conducting a CSO Master Plan study on a schedule approved by the
department;
(2) The licensee is
implementing the approved Master Plan; or
(3) The licensee has completed implementation
of the approved Master Plan.
B.
Review and documentation. In
the cases of Section 8(A)(2) and Section 8(A)(3) above, the licensee must
implement additional abatement measures, if necessary, to ensure that the
additional wastewater will not exceed the targeted level of control or extend
the implementation schedule in the approved Master Plan (see Section
3(B)(2)(b)(vi). In the case of Section 8(A)(1) above, the licensee must
document practices, measures, or programs to mitigate impacts to the combined
sewer system from the added wastewater. The licensee must consider, but is not
limited to any combination of the following:
(1) Implementation of the nine minimum
controls as described in Section 5, above;
(2) Removal of extraneous, uncontaminated
water from private or public sources;
(3) Physical improvements, alterations, or
upgrades that result in reduced CSO activity;
(4) Pollution prevention programs;
or
(5) Sewer separation
projects.
C.
Submissions. Documentation of additions of wastewater to the combined
sewer system, and associated mitigating measures must be included in the yearly
CSO progress reports (see Section 7(H) ). Reports must contain the volumes and
characteristics of wastewater added or authorized for addition and descriptions
of sewer system improvements and estimated effectiveness.
NOTE: Stormwater runoff may contain various pollutants.
Before separation projects are carried out, care should be taken to assure
runoff borne pollutants are not simply redirected to the receiving water
through another piping system. This is of particular concern in heavily
developed areas where pollutant concentrations are likely to be higher.
Licensees proposing sewer separation projects should investigate methods to
control pollutants from the separated stormwater, such as the treatment and
detention of stormwater through the use of stormwater Best Management Practices
and reduction of stormwater runoff. Redirection of stormwater to areas
supporting less sensitive uses or areas where fewer environmental impacts will
result should also be considered.
