Current through Register Vol. 48, No. 38, September 20, 2024
a)
1) All
grantees whose grant assistance is awarded after July 1, 1973 must demonstrate
to the satisfaction of the Agency that each sewer system discharging into the
treatment works project for which the grant offer is made is not or will not be
subject to excessive infiltration/inflow. The determination whether excessive
infiltration/inflow exists may take into account, in addition to flow and
related data, other significant factors such as cost-effectiveness (including
the cost of substantial treatment works construction delay), public health
emergencies, the effects of plant bypassing or overloading, or relevant
economic or environmental factors.
2) The determination whether or not excessive
infiltration/inflow exists will generally be accomplished through a sewer
system evaluation consisting of:
A) An
infiltration/inflow analysis; and, if appropriate,
B) A sewer system evaluation survey followed
by rehabilitation of the sewer system to eliminate any excessive
infiltration/inflow defined in the sewer system evaluation.
b) The
infiltration/inflow analysis shall demonstrate the non-existence or possible
existence of excessive infiltration/inflow in each sewer system tributary to
the treatment works. The analysis should identify the presence, flow rate, and
type of infiltration/inflow conditions which exist in the sewer systems.
Information to be obtained and evaluated in the analysis should include, to the
extent appropriate, the following:
1)
Estimated flow data at the treatment facility, all significant overflows and
bypasses, and, if necessary, flows at key points within the sewer
system.
2) Relationship of existing
population and industrial contribution to flows in the sewer system.
3) Geographical and geological conditions
which may affect the present and future flow rates or correction costs for the
infiltration/inflow.
4) A
discussion of age, length, type, materials of construction and known physical
condition of the sewer system.
5)
For determination of the possible existence of excessive infiltration/inflow,
the analysis shall include an estimate of the cost of eliminating the
infiltration/inflow conditions. These costs shall be compared with estimated
total costs for transportation and treatment of the
infiltration/inflow.
6) If the
infiltration/inflow analysis demonstrates the existence or possible existence
of excessive infiltration/inflow, a detailed plan for a sewer system evaluation
survey shall be included in the analysis. The plan shall outline the tasks to
be performed in the survey and their estimated costs.
7) The sewer system evaluation survey shall
consist of a systematic examination of the sewer systems to determine the
specific location, estimated flow rate, method of rehabilitation and cost of
rehabilitation, method of rehabilitation and cost of rehabilitation versus cost
of transportation and treatment for each defined source of
infiltration/inflow.
8) The results
of the sewer system evaluation survey shall be summarized in a report. In
addition, the report shall include:
A) A
justification for each sewer section cleaned and internally
inspected.
B) A proposed
rehabilitation program for the sewer systems to eliminate all defined excessive
infiltration/inflow.
C) Exception
In the event it is determined by the Agency that the
treatment works would be regarded (in the absence of an acceptable program of
correction) as being subject to excessive or possible excessive
infiltration/inflow, grant assistance may be offered provided that the grantee
establishes to the satisfaction of the Agency that the treatment works project
for which grant application is made will not be significantly changed by any
subsequent rehabilitation program or will be a component part of any
rehabilitation system: Provided, That the grantee agrees to complete the sewer
system evaluation and any resulting rehabilitation on an implementation
schedule, which shall be inserted as a special condition in this grant
agreement.
