SECTION 252:626-17-1. General

(a)   Construct tanks of reinforced concrete or steel in accordance with AWWA standard specifications. Adequately protect steel tanks against corrosion.

(b)   Provide all tanks with a bypass.

(c)   Provide safety equipment in accordance with OSHA standards.

(d)   Maintain sufficient storage capacity to meet domestic demands and fire flow demands, where fire protection is provided.

(1)   Satisfy fire flow requirements pursuant to the International Fire Code, published by the International Code Council, Inc., 2003 Edition, Distribution System Requirements for Fire Protection, M 31, published by the AWWA, 3^rd Edition where fire protection is provided.

(2)   Systems not providing fire protection are required to maintain a minimum storage capacity of 24 hours capable of delivering 25 psi throughout the distribution system.

(e)   Location of standpipes and finished water storage.

(1)   Place the bottom of standpipes on a suitable foundation at the normal ground surface and above the 100-year flood plain.

(2)   When the bottom of a finished water storage structure must be below normal ground surface, place it above the ground water table. Sewers, drains, standing water, and similar sources of possible contamination must be kept at least 50 feet from the finished water storage structure. Do not locate below ground finished water storage structures within 20 feet of a sanitary sewer or 50 feet from pressure sewer lines.

(3)   The top of a reservoir must be at least two feet above the normal ground surface. Clearwells constructed under filters may be exempted from this requirement when the total design gives the same protection.

(f)   Protection.

(1)   Cover of finished water storage. Storage of treated water must have a watertight roof or cover, which will exclude birds, animals, insects and excessive dust. Locate the top of all finished water storage structures above possible flood elevations.

(2)   Protection from trespasses. Provide fencing, locks on access manholes, and other necessary precautions to prevent vandalism, pilfering, trespassing, or sabotaging.

(3)   Cathodic protection shall be provided for all steel tanks to prevent under bottom corrosion.

(g)   Drains. Connection through a 6 inch air gap or two pipe diameters of the drain whichever is greater is allowed.

(h)   Overflow. Provide all water storage structures with an overflow that terminates at an elevation between 12 and 24 inches above the ground surface, and release water over a drainage inlet structure or splash plate.

(1)   Do not connect the water storage structure overflow line to a sewer or storm drain.

(2)   Locate all overflow pipes so that any release of water is visible.

(3)   Equip the ends of the pipes with flex gates.

(4)   Design the overflow pipe with sufficient diameter to permit wasting of water in excess of the filling rate.

(i)   Access. Design finished water storage structures with convenient access to the interior for cleaning and maintenance. Manholes located on top of storage structures must:

(1)   be surrounded with a frame at least 4 inches in height above the surface of the roof at the opening,

(2)   be elevated 24 to 36 inches above the top of sod covering ground level structures,

(3)   be fitted with a solid watertight cover, which overlaps the framed opening and extends down around the frame at least 2 inches,

(4)   be hinged at one side, and

(5)   have a locking device.

(j)   Vents. Vent all finished water storage structures. Overflows are not considered vents. Open construction between the side wall and roof is not allowed. Design of vents must:

(1)   prevent the entrance of surface water, rainwater, birds, insects and animals,

(2)   limit the introduction of dust,

(3)   terminate in an inverted U with the opening 24 to 36 inches above the roof or sod covering on ground-level structures, and

(4)   be covered with a 24 mesh corrosion resistant screen installed at a location least susceptible to vandalism.

(k)   Roof and side wall. Make the roof and side walls of all structures watertight with no openings except properly constructed vents, manholes, overflows, risers, drains, pump mountings, control ports, and piping for inflow and outflow.

(1)   Any pipes running through the roof or side wall of a metal finished water storage structure must be welded, or properly gasketed. In concrete storage structures, connect pipes to standard wall castings poured in place during the forming of the concrete. The wall castings must have seepage rings imbedded in the concrete.

(2)   Curb and properly sleeve all openings in the storage structure roof or top to prevent entrance of surface water or floor drainage into the structure.

(3)   Locate valves and controls outside the storage structure so that valve stems and similar projections will not pass through the roof or top of the structure.

(l)   Drainage of roof. The roof of the storage structure must be well drained and designed not to hold water or snow. Do not allow downspout pipes to enter or pass through the reservoir.

(m)   Freezing. Design finished water storage structures and their appurtenances to prevent freezing.

(n)   Internal catwalk. Every catwalk over finished water in a storage structure must have a solid floor with raised edges so shoe scrapings and dirt will not fall into the water.

(o)    Outlet piping. Locate the outlet pipes from all storage structures in a manner that will prevent the flow of sediment into the distribution system.

(p)   Grading. Grade the area surrounding a ground level structure to prevent surface water from standing within 50 feet of the structure.

(q)   Painting and cathodic protection. Provide proper protection to metal surfaces by paints or other protective coatings. Paint systems must be listed by NSF or UL as meeting the ANSI/NSF Standards for contact with potable water. Cathodic protective devices are required where soil conditions warrant.

(r)   Disinfection. Disinfect finished water storage structures in accordance with AWWA standard specifications.

[Source: Added at 18 Ok Reg 1612, eff 6-1-01; Amended at 25 Ok Reg 2304, eff 7-11-08]