Current through September 21, 2024
The design and construction of animal waste and wastewater
collection systems for confined swine feeding operations shall meet the
following minimum standards:
(a)
Gutters and trenches that do not have a constant hydraulic head against the
joints or the structure, such as those designed to be free draining and are
frequently flushed or scraped, shall have a watertight design.
(i) Construction shall be of air entrained
concrete with a 28-day compressive strength of 4000 psi or better. The minimum
thickness of any section shall be four (4) inches. All joints shall be keyed
construction and sealed with a high quality elastomeric caulk. Any other
materials proposed for gutter construction shall be evaluated under the
provisions of Section 31 of these regulations.
(ii) Flushing gutters shall have a minimum
grade of 0.4 percent.
(iii) Gutters
shall be flushed at least every 12 hours or scraped once each 48 hours. Each
gutter shall be inspected weekly and any build ups removed or freed using
manual scraping or pressure washers.
(iv) Gutters shall be cleaned and visually
inspected at least annually for water tightness. Any probable leaks shall be
repaired immediately.
(b) Gutters and trenches that normally retain
manure and flush water and are subject to a constant hydraulic head shall be
described as pull plug gutters. Any waste containment structures normally
subject to hydraulic head, including pull plug gutters, shall have secondary
containment with a leak collection and recovery system.
(i) Construction shall be of air entrained
concrete with a 28-day compressive strength of 4000 psi or better. The minimum
thickness of any section shall be four (4) inches. All joints shall be keyed
construction and sealed with a high quality elastomeric caulk. All expansion
joints shall have bulb type water stops. Any other materials proposed for
gutter construction will be evaluated under the provisions of Section
31.
(ii) The secondary containment
shall consist of a geomembrane at least 20 mils thick installed by the
manufacturer's recommendations, a geosynthetic clay liner or a compacted clay
liner at least one foot thick with a permeability of 1 X
10-6 cm/sec or less. Compacted clay liners shall be
constructed, tested, and certified in accordance with the provision of Section
35(d)(i)(A). The secondary containment shall be graded to the recovery system
with a minimum grade of 0.4 percent.
(iii) The secondary containment surfaces
shall drain by gravity into the recovery system. The recovery pump shall have a
totalizing hour meter and a high level alarm.
(A) The amount of the liquids being recovered
from the secondary containment surface shall be determined and recorded on a
weekly basis. If the calculation of liquids recovered exceeds sixty (60)
gallons/week/thousand square feet of confinement building, repair of the
gutters and trenches must be completed within six (6) months. The permittee
shall report any exceedance of this rate to the Division within seven (7)
days.
(B) If the high level alarm
is activated or the recovery rate exceeds 120 gallons/week/thousand square feet
of confinement building the gutters must be drained immediately and operated as
free draining, daily flush type gutters until repairs are made. The permittee
shall report any exceedance of this rate to the Division within 48
hours.
(iv) Pull plug
gutters shall be charged to a minimum depth of six (6) inches with fresh or
recycled water before receiving animal wastes.
(v) A minimum clearance of six (6) inches
must be maintained between the top of the animal waste and the bottom of the
trench cover.
(vi) Pull plug
gutters shall be drained and recharged at least every fourteen (14)
days.
(c) Collection
lines convey animal waste and flush water from the gutters and trenches to
treatment or storage facilities. This section contains the minimum standards
for the design and construction of animal waste piping and transfer systems.
(i) Collection lines shall be designed to
accommodate the maximum instantaneous flows. If storm water is collected and
introduced to the animal waste treatment or storage facilities, the design of
the collection system and the treatment or storage system shall be adequate to
accommodate the maximum instantaneous and annual precipitation rates.
(ii) Collection line layouts shall allow
isolation of individual lines for testing and cleaning.
(iii) Pipe materials shall resist acid and
alkaline solutions, organic solvents, and other animal waste constituents and
environmental conditions encountered.
(iv) Pipe materials shall be chosen and the
pipeline shall be designed to withstand all trench and superimposed surface
live loads with a minimum factor of safety. Rigid pipes shall have a minimum
factor of safety of 1.5, and flexible pipes shall have a minimum factor of
safety of 1.25.
(v) Piping shall be
tested for integrity after all trenches are backfilled. The testing results
shall be certified by a Wyoming licensed engineer. Leakage tests shall be
infiltration, exfiltration, or air tests. All flexible piping shall be tested
for deflection. Deflection tests shall be made with a mandrel or other
technology producing comparable data.
(A)
Infiltration or exfiltration shall not exceed a maximum of 200 gallons per inch
diameter per mile per day (1200 liters/cm/km/day) with a minimum of two (2)
feet (0.6 m) of head over the top of the pipe.
(B) Air tests shall conform to ASTM
C-828-80.
(C) A maximum five (5)
percent deflection after flexible pipe is backfilled for thirty (30) days is
allowed. A mandrel of 95 percent of pipe diameter shall be used. No mechanical
pulling of a mandrel is permitted.
(vi) Potable water shall be protected
according to the AWWA Manual M14, which addresses cross-connection
control.
(vii) If animal waste or
waste water is pumped, the pumping station shall be designed if possible so
that failure shall not result in any release. If such design is not possible, a
redundant, fail safe design of the pumping station shall be required.
(d) Gravity drained lines shall be
tested at least every five (5) years for leakage according to Section 33(c)(v)
of these regulations. Test results shall be included in the annual report.
Lines failing the leakage test shall be repaired within thirty (30) days. After
repair, the integrity of the line must be verified by retesting.
(e) Pressure lines shall be tested annually
for leakage according to Section 33(c)(v)(A). Test results shall be included in
the annual report. Lines failing the leakage test shall be removed from service
and repaired immediately. After repair, the integrity of the line must be
verified by retesting.
