(ii) The designing engineer should consider such items
as permanently buried mains with readily accessible valve boxes, two
or more lateral lines, and quick coupling valves at the main/lateral
connections.
(iii) Cross connection with a potable water supply
system is prohibited. Cross connection with a well water system will
be reviewed on a case-by-case basis.
(C) Vehicular access to conveyance system locations
and equipment should be provided at intervals of 1,000 feet to 1,300
feet.
(D) The cover crop of each wastewater application area
shall be harvested a minimum of once per year. Consideration should
be given to the selection of crops which will allow two or more harvests
per year to be made.
(E) All effluent applied as irrigation water should
have a pH within the range of 6.0 to 9.0.
(c) Percolation. Percolation application systems provide
for ultimate application of the wastewater by evaporation and percolation
with no resulting discharge to surface water in the state.
(1) Percolation systems will not be permitted in those
locations where seepage would adversely affect the uses of groundwater
resources.
(2) Primary treatment of the raw sewage shall be provided
prior to land application.
(3) Percolation systems shall be limited to sites having
soil textures suitable for sustaining a rapid intake rate. Percolation
dosing sites shall be limited to soils classified as sands, loamy
sands, or sandy loams having a minimum infiltration rate of six inches
per hour.
(4) Multiple dosing basins shall be provided for the
application of wastewater. The wastewater distribution system shall
be designed to provide a maximum dosing period of 24 hours upon any
individual dosing basin and a minimum resting period for any individual
dosing basin of five days following a period of dosing.
(5) The hydraulic loading rate will be considered on
a case-by-case basis. The designing engineer shall identify the permeability
of the limiting soil layer.
(6) The design shall provide an area equal to a minimum
of 20% of the total application site area for the construction of
wastewater storage for use during periods of wet or freezing weather
and to provide flexibility of dosing site use.
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