The following elements must be included in a CSO Master Plan
by the licensee.
A.
CSO
assessment and monitoring. The complexity of sewerage systems and CSO
discharge situations varies greatly from one community to another.
Consequently, it is recognized that the scope and magnitude of assessment and
monitoring needs must be adapted to each individual community. The description
of activities below is intended to reflect the magnitude and nature of
assessment and monitoring which may be done in a comprehensive study. Depending
on individual community needs, a licensee may expect to tailor an individual
program. Not all activities will be required of all licensees.
(1) The CSO assessment is conducted to
determine existing conditions and sewerage system characteristics. The
assessment may include, but is not limited to:
(a) Mapping of the existing sewer system and
descriptions of flow control structures, pumping stations and treatment
facilities;
(b) Reviewing current
operational practices and identifying known problems or system
shortcomings;
(c) Describing
drainage areas served by the sewerage system, including land uses and
significant sources of wastewater;
(d) Locating wastewater discharges and CSO
discharge points to receiving waters within the study area; and
(e) Describing and mapping receiving waters,
with particular attention to existing and designated uses under state water
quality standards, characterization of historic impairments of uses, and
identification of high value or potential uses that may be realized with CSO
abatement.
(2) CSO
discharge points must be observed and either flow monitored or modeled over a
period of time sufficient to reflect a wide range of storm events and
antecedent conditions in order to determine CSO activity. Additionally, flow
monitoring must be conducted at a number of locations adequate to allow
estimation of flows within the entire sewer system. Flow monitoring must be
representative of the sewerage system's drainage area and include varied land
uses, unless otherwise approved by the department. The number and location of
flow monitoring points will vary with characteristics of individual systems and
the means used to evaluate the system. Also, the period of monitoring time
needed to obtain sufficient data will vary depending on the weather conditions.
Typically, the use of computer modeling of a system will reduce the need for
flow monitoring.
(3) In conjunction
with flow monitoring, testing is to be conducted on flow-weighted, composite
samples, or grab samples, depending on applicability, to determine pollutant
loads. Samples must be collected to characterize the so-called first flush, and
the total discharge volume. Samples must be analyzed for total suspended
solids, biochemical oxygen demand and bacteria. The department, on the basis of
receiving water sensitivity, known discharge constituents of concern, or local
concerns, may specify analysis for other pollutants. Normally, samples must be
collected during four separate discharge events, two in the spring and two in
the summer, at each location.
(4) A
sampling program must be conducted to determine the impact of CSO discharges on
the receiving water. Sampling locations must be selected to reflect typical
conditions and the impact on existing local uses including contact recreation
and boating. Unless warranted by particular receiving water quality concerns,
samples must be analyzed for bacteria only. Sampling is not required for
bacteria if the licensee informs the department that water quality impacts
exist by specifying the nature, area and duration of impacts due to CSO
discharges.
The department, upon receiving information characterizing CSO
discharges, shall assist the licensee in assessing area-wide impacts.
(5) Concurrent with CSO
monitoring, evaluation of the sewer system must be conducted to identify
sources of extraneous water entering the system. To the extent they are
available, previous inflow/infiltration analyses or other sewer system studies
may be used when appropriate.
(6)
Along with monitoring and assessment, public comment and involvement must be
sought. Particular consideration must be given to identifying public goals,
potential designated uses and priorities for use of receiving waters and CSO
abatement technologies.
B.
Prioritization and alternative
analysis. A major element of a CSO Master Plan is the identification of
existing and potential high value uses. The involvement of the public is
essential during this identification and prioritization process. The Master
Plan must place high priority on abatement of combined sewer overflows that
affect waters having the greatest potential for public use or benefit and
attempt to relocate any remaining discharges to areas where minimal impacts or
losses of uses would occur. Another major element of a CSO Master Plan is a
thorough analysis of alternatives for CSO abatement, which includes a financial
capability analysis to determine user cost of the recommended alternative, and
an implementation schedule for the recommended abatement program.
(1) Prioritization of CSO discharge abatement
must be based on data from the CSO assessment and monitoring program, and any
other existing relevant data. Priorities for abatement include, but are not
limited to the following list, shown in order of importance. The order and
number of items may change, as determined by the department, if a licensee
shows justification for the change.
(a)
Discharges that occur during dry weather periods;
(b) Discharges that may impact public
drinking water intakes;
(c)
Discharges that may impair water contact recreational uses or create public
health concerns in the receiving waters;
(d) Discharges that discharge into areas
determined to have redeemable shellfish resources or important fish or wildlife
habitat;
(e) Discharges that
contain industrial or medical wastes;
(f) Discharges that function during the
months of June through September;
(g) Discharges that cause localized nuisance
conditions; and
(h) All other CSO
discharges.
(2) The
licensee shall conduct an evaluation of a full range of control alternatives.
(a) These alternatives must include, but are
not limited to:
(i) Pollution prevention
practices to reduce, control, or eliminate pollutants at their source and prior
to entry into the sewerage system;
(ii) Removing sources of uncontaminated water
introduced into the sewerage system from private and public sources;
(iii) Maximizing the existing sewerage system
for storage, transport and treatment of wastewater;
(iv) Off-line storage or retention of excess
flow for addition to the sewerage system as its capacity allows;
(v) Sewer separation to remove stormwater
from sanitary wastewater;
(vi) Full
elimination of CSOs;
(vii) Treatment
of CSOs (see Section 4); and
(viii) Discharge point relocation to less
sensitive receiving waters.
(b) This evaluation process consists of the
following steps:
(i) Developing a list of
available control measures; and
(ii) Screening the list to eliminate those
measures that for various reasons would not warrant further consideration for
the given application. The list of available control measures must be developed
by evaluating each measure's ability to reduce pollutants of concern that would
cause violations of water quality standards. The pollutants would have
previously been identified during the CSO Assessment and Monitoring Phase (see
Section 3(A)).
The list of available control measures must be screened using
appropriate criteria. Typical screening criteria can be considered under these
main categories:
a. Performance
factors, relating to the effectiveness of control measures;
b. Implementation and operation factors,
relating to the licensee's ability to implement and manage the control
measures;
c. Environmental impacts,
relating to possible negative side-effects from constructing control measures;
and
d. Comparative capital and
operation and maintenance costs, with an analysis of the licensee's ability to
pay for such costs.
NOTE: This screening criteria, along with the use of Best
Management Practices and the prioritization of high value use areas, allow the
community to focus on the most appropriate control measures to solve its
specific CSO control needs.
(iii) CSO discharges that will remain
following implementation of a Master Plan must be located to receive maximum
dispersion and dilution or maximum environmental benefit in the receiving
water. All efforts must be made to locate these discharge points away from
sensitive areas or high value uses in the receiving water or where existing or
expected uses may be impaired.
(iv)
The effectiveness of current and potential best management practices (see
Section 5) must be evaluated.
(v)
A financial capability analysis must be completed to evaluate the impact of
proposed CSO abatement alternatives on sewer user rates. The analysis must show
the proposed residential user charge as a percentage of the Medium Household
Income (MHI) for the community.
(vi) A plan must be included that
accommodates projected additions to the sewer system while maintaining CSO
abatement goals and implementation timetables.
(3) Adequate public participation efforts
must be made during and after the planning process.
(a) Development of the Master Plan and
subsequent reviews and updates must include public participation efforts that
are adequate to inform and receive comments from persons interested in water
quality or abatement issues associated with CSO discharges. These efforts must
include providing the public with information on CSO assessments, water quality
impacts, abatement alternatives, and costs and related issues. Public
discussion of water quality, current receiving water uses, desired potential
uses, priority of uses, acceptable abatement technologies and financial
capability must be sought. The licensee must hold a public hearing on the
Master Plan and provide the department with a record of the hearing, a list of
people in attendance, copies of written testimony and the licensee's responses
to the issues raised. The hearing must be advertised no less than 30 days nor
more than 45 days prior to the hearing in a local newspaper of general
circulation in the area affected by CSO discharges. Concurrent with the
advertisement, a notice of the public hearing must be sent to all persons who
have expressed an interest in the Master Plan. A licensee that plans to apply
for State Revolving Fund (SRF) loans must comply with public hearing
requirements in the State of Maine Revolving Loan Fund Rules, Chapter 595.
Records of public participation efforts and the public hearing must be
maintained and be available to the department.
(b) In cases where a CSO may cause continuing
or future impairment of water quality criteria or uses, the licensee of these
discharges must institute ongoing efforts to inform the public of those
impacts. The means and frequency of notices must be specific to the geographic
area and uses involved in order to gain maximum public awareness. However, a
minimum notification program must consist of:
(i) Timely annual publication of prominent
notices in newspapers having general circulation in the area affected by CSO
discharges;
(ii) Posting of
permanent signs, where feasible, at locations that afford public access to
water affected by CSO discharges such as parks and boat launches; and
(iii) Direct written contact with persons
known to have particular interest in the use of land or waters affected by CSO
discharges.
In individual situations, other comparable means of public
notification may be substituted for those above if they are shown to be equally
effective.
All notices must include a description of the area and uses
impacted by CSO discharges, the nature, times and conditions of impacts, and
precautions that should be observed by the public.
C.
Implementation schedule. An implementation schedule for completion of
recommended CSO abatement technologies and programs must be included. Due to
the nature of emerging CSO abatement technologies, changing growth patterns and
financial conditions within communities, and other unforeseen factors, the
schedule must include periodic updates and reviews of the Master Plan. These
updates allow the licensee to modify the implementation plan based on results
of the continuing monitoring program (see Section 6) and experience gained,
while keeping focused on the original goals of the Master Plan. A length of
time between reviews of three to five years may be reasonable, depending on
progress made on implementation of the Master Plan.
D.
Proposed Budget. A proposed
budget needed to accomplish the recommended CSO abatement implementation
program must be included.
