Alaska Administrative Code
Title 18 - Environmental Conservation
Chapter 72 - Wastewater Treatment and Disposal
Article 2 - Domestic Wastewater System Plan Review
18 AAC 72.270 - Collection and pumping systems
Universal Citation: 18 AK Admin Code 18 AAC 72.270
Current through November 28, 2024
(a) Plans for construction of a collection and pumping system must include
(1) the items required to be submitted under
18 AAC 72.205;
(2) plans and profiles for sewer mains and
community sewer lines to include manholes and lift stations with invert
elevations;
(3) design
calculations, design criteria, and specifications for
(A) design flows, pipe size, and pipe
materials;
(B) hydraulic grade line
considerations associated with pressurized portions of a sewer line;
(C) vacuum sewer lift segments;
(D) pump station, collection station, or
surge tank capacities;
(E)
overflows, alarms, solids handling, provisions for servicing, and emergency
operations;
(F) manhole or cleanout
placement, and methods for cleaning the collection system;
(G) siting with respect to health hazards,
nuisance potential, stream crossings, and flooding;
(H) bedding and backfill;
(I) thermal protection considerations;
and
(J) provisions for steep slope
and high velocity protection if applicable.
(b) A collection and pumping system design must include the following criteria:
(1) the
mean conduit velocity, when flowing full, is not less than two feet per second
for the collection system design;
(2) pipe sizes adequate for the maximum
expected flow and designed so that the diameter of any receiving sewer line is
equal to or greater than the diameter of the largest sewer line connecting to
it;
(3) the alignment of a gravity
sewer line between manholes shall be straight and at a uniform slope; a manhole
must be installed at changes in pipe slope, size, alignment, and at
intersections;
(4) the location
meets the minimum separation distance requirements
(A) under 18 AAC 80 for public water systems
unless the department has approved a lesser separation distance under that
chapter;
(B) under
18 AAC 72.100 for private water
systems unless the department has approved a lesser separation distance under
this chapter; and
(C) of 100 feet
between the mean annual high water level of a lake, river, stream, spring, or
slough, or the mean higher high water level of tidally influenced coastal
waters and a tank, lift station, or sewer manhole, measured horizontally from
nearest edge to nearest edge;
(5) pump stations and collection stations,
other than those designed for pumping from individual service connections or
onsite septic tanks, must be equipped with at least two pumps, each of which
can handle flows equal to or in excess of the design flow;
(6) pump stations must be equipped with an
audible and visual high water alarm;
(7) the system does not receive stormwater or
silty water from construction dewatering efforts, gutter runoff, or street
runoff into a sewer designed to handle only domestic wastewater or nondomestic
wastewater without stormwater;
(8)
the system discharges to an approved wastewater treatment works with adequate
capacity;
(9) the system does not
collect oil, petroleum products, industrial solvents, or other substances
(A) into a sewer designed to handle only
domestic wastewater or stormwater; or
(B) that will be received by a treatment
works or disposal system that is not designed and approved to handle these
substances; and
(10) if
proposing to discharge to an existing collection system, documentation must be
provided showing that
(A) the receiving system
has sufficient capacity to accommodate flows expected from the proposed
discharge;
(B) the receiving system
is permitted or approved to accept the type of wastewater proposed;
and
(C) the owner of the receiving
system has approved the discharge.
Authority:AS 44.46.020
AS 46.03.010
AS 46.03.020
AS 46.03.050
AS 46.03.100
AS 46.03.110
Disclaimer: These regulations may not be the most recent version. Alaska may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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