Wyoming Administrative Code › Agency 020 - Environmental Quality, Dept. of › Sub-Agency 0011 - Water Quality › Chapter 20 - PERMITTING, DESIGN AND OPERATION STANDARDS CONFINED SWINE FEEDING OPERATIONS › Part C - DESIGN AND OPERATION STANDARDS › Section 20-34 - Animal Waste Storage Facilities

Current through July 13, 2024
The design and construction of animal waste storage
					 facilities for confined swine feeding operations shall meet the following
					 minimum standards:
(a) Animal waste
				  storage structures shall be required to have secondary containment and liquid
				  recovery systems incorporated because they are subject to a constant hydraulic
				  head.
(b) A total minimum animal
				  waste storage capacity equal to nine (9) months waste production shall be
				  provided to allow for the limited periods when manure slurries may be land
				  applied.
(c) The design of the
				  operational unit shall permit any animal waste storage structure to be removed
				  completely from service for repair without significant impact to the feeding
				  operation.
(d) Concrete
				  construction shall conform to recommendations of the "Concrete Manure Storage
				  Handbook," MWPS-36 dated 1994, or later version as adopted by division policy,
				  published by the MidWest Plan Service and available from the land grant
				  universities of the North Central Region.
(e) Structures interior to or beneath swine
				  housing facilities constructed of concrete, shall meet the following
				  requirements: (Construction of other materials shall be addressed pursuant to
				  Section 31 of these regulations.)
(i)
				  Construction shall be of air entrained concrete with a 28-day compressive
				  strength of 4000 psi or better. All joints shall be keyed construction and
				  sealed with a high quality elastomeric caulk. All expansion joints shall have
				  bulb type water stops.
(ii) The
				  secondary containment shall consist of a geomembrane liner at least 30 mils
				  thick installed according to the manufacturer's recommendations, a geosynthetic
				  clay liner, or a compacted clay liner at least one (1) 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.
(A) 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.
(B) 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
				  storage tank or pit must be completed within six (6) months. The permittee
				  shall report any rate greater than this to the Division within seven (7)
				  days.
(C) If the recovery rate
				  exceeds 120 gallons/week/thousand square feet of confinement building, the
				  storage facility must be emptied within sixty (60) days and repairs made. The
				  permittee shall report any rate greater than this to the Division within 48
				  hours.
(D) If the high alarm level
				  is reached, the Division must be notified immediately. The storage tank must be
				  emptied immediately.
(iii) Animal waste shall not be allowed to
				  accumulate to within one (1) foot of the bottom of the floor slats.
(iv) Interior or under floor animal waste
				  storage facilities shall be mechanically ventilated. If the exhaust gas from
				  this mechanical ventilation is determined to be a source of problem odors,
				  treatment of the exhaust gas shall be required. A positive odor control
				  technology resulting in either the adsorption or destruction of the odor
				  causing gases shall be installed.