Iowa Administrative Code › Agency 567 - Environmental Protection Commission › Title II - Air Quality › Division B › Chapter 43 - Water Supplies-design and Operation › Rule 567-43.3 - Public Water Supply System Construction

Current through Register Vol. 47, No. 3, July 24, 2024
(1)
Standards for public water
				  supplies.
Any public water supply that does not meet the drinking
				  water standards contained in 567-Chapters 41 and 43 shall make the alterations
				  in accordance with the standards for construction contained in 43.3(2)
				  necessary to comply with the drinking water standards unless the public water
				  supply has been granted a variance from a maximum contaminant level or
				  treatment technique as a provision of its operation permit pursuant to
				  567-43.2 (455B), provided that
				  the public water supply meets the schedule established pursuant to
				  567-43.2 (455B). Any public
				  water supply that, in the opinion of the director, contains a potential hazard
				  shall make the alterations in accordance with the standards for construction
				  contained in this rule necessary to eliminate or minimize that hazard. A system
				  that is not operating within the design standards may be required by the
				  department via a compliance schedule to upgrade the deficient areas of the
				  system before a construction permit will be issued for any work in the system
				  that does not address the current deficiencies.
(2)
Standards for
				  construction.
a. The standards for a
				  project are the Ten States Standards as adopted through 2012 and the American
				  Water Works Association (AWWA) Standards as adopted through 2016 and 43.3(7) to
				  43.3(9). To the extent of any conflict between the Ten States Standards and the
				  American Water Works Association Standards and 43.3(7) to 43.3(9), the Ten
				  States Standards, 43.3(2), and 43.3(7) to 43.3(9) shall prevail. Additional
				  standards include the following:
(1) Polyvinyl
				  chloride (PVC) pipe manufactured in accordance with ASTM D2241, AWWA C900, AWWA
				  C905, ASTM F1483, or AWWA C909 may be used for water main construction. The
				  maximum allowable pressure for PVC or polyethylene (PE) pipe shall be
				  determined based on a safety factor of 2.0 and a surge allowance of no less
				  than two feet per second (2 fps).
(2) For CWS groundwater systems, a minimum of
				  two wells shall be provided, unless the system demonstrates to the department's
				  satisfaction that a single well will provide a reliable and adequate source.
				  For NTNC and TNC groundwater systems, a single well is acceptable.
(3) Separation of water mains from sanitary
				  and combined sewers.
1. Horizontal separation
				  of water mains from gravity sanitary and combined sewers. Water mains shall be
				  separated from gravity sanitary and combined sewer mains by a horizontal
				  distance of at least ten feet measured edge to edge unless the bottom of the
				  water main is at least 18 inches above the top of the sewer, and either:
* The water main is placed in a separate trench, or
* The water main is located on a bench of undisturbed earth
					 at a minimum horizontal separation of three feet from the sewer.
If it is not possible to obtain a horizontal separation of
					 three feet and a vertical separation of 18 inches between the bottom of the
					 water main and the top of the sewer, a linear separation of at least two feet
					 shall be provided, and one of the following shall be utilized:
* The water main shall be enclosed in watertight casing
					 pipe with an evenly spaced annular gap and watertight end seals, or
* The sewer shall be constructed of water main
					 materials.
The separation distance between the water main and the
					 sewer shall be the maximum feasible in all cases.
2. Horizontal separation of water mains from
				  sanitary sewer force mains. Water mains shall be separated from sanitary sewer
				  force mains by a horizontal distance of at least ten feet measured edge to edge
				  unless the sanitary sewer force main is constructed of water main materials and
				  the water main is laid at least four feet horizontally from the sanitary sewer
				  force main. The separation distance between the water main and the sanitary
				  sewer force main shall be the maximum feasible in all cases.
3. Vertical separation of water mains from
				  sanitary and combined sewer crossovers. Vertical separation of water mains
				  crossing over any sanitary or combined sewers shall be at least 18 inches when
				  measured from the bottom of the water main to the top of the sewer. If it is
				  not possible to maintain the required vertical separation, one of the following
				  shall be utilized:
* The bottom of the water main shall not be placed closer
					 than six inches above the top of a sewer, or
* The top of the water main shall not be placed closer than
					 18 inches below the bottom of a sewer.
When a water main crosses below or less than 18 inches
					 above a sanitary or combined sewer, one of the following shall be utilized
					 within ten feet measured edge to edge horizontally, centered on the
					 crossing:
* The water main shall be enclosed in watertight casing
					 pipe with an evenly spaced annular gap and watertight ends, or
* Sewer pipe of water main material shall be
					 installed.
The separation distance shall be the maximum feasible in
					 all cases. Wherever a water main crosses a sanitary or combined sewer, the
					 water main and sanitary or combined sewer pipes must be adequately supported. A
					 low permeability soil shall be used for backfill material within ten feet of
					 the point of crossing along the water main.
4. Horizontal separation of water mains from
				  sanitary and combined sewer manholes. No water pipe shall pass through or come
				  in contact with any part of a sanitary or combined sewer manhole. A minimum
				  horizontal separation of three feet shall be maintained.
(4) Separation of water mains from storm
				  sewers.
1. Horizontal separation of water
				  mains from gravity storm sewers. Water mains shall be separated horizontally
				  from gravity storm sewers by at least ten feet measured edge to edge. If it is
				  not possible to maintain the required horizontal separation of ten feet, a
				  minimum of three feet of separation shall be maintained and one of the
				  following shall be utilized within ten feet measured edge to edge:
* The water main shall be constructed of ductile iron pipe
					 with gaskets impermeable to hydrocarbons, or
* The water main shall be enclosed in watertight casing
					 pipe with an evenly spaced annular gap and watertight end seals, or
* Storm sewer pipe of water main material shall be
					 installed, or
* Reinforced concrete pipe storm sewers shall be
					 constructed with gaskets manufactured in accordance with ASTM
					 C443.
2. Vertical separation
				  of water mains from storm sewer crossovers. Water mains shall be vertically
				  separated from storm sewers by at least 18 inches between the outside edges of
				  the water main and the storm sewer. The separation distance shall be the
				  maximum feasible in all cases. In all cases where a water main crosses a storm
				  sewer, the water main and storm sewer pipes must be adequately supported. A low
				  permeability soil shall be used for backfill material within ten feet of the
				  point of crossing along the water main. If it is not possible to obtain 18
				  inches of vertical separation where the water main crosses above a storm sewer,
				  a minimum of 6 inches vertical separation shall be maintained and one of the
				  following shall be utilized within ten feet measured edge to edge horizontally,
				  centered on the crossing:
* The water main shall be constructed of ductile iron pipe
					 with gaskets impermeable to hydrocarbons, or
* The water main shall be enclosed in watertight casing
					 pipe with an evenly spaced annular gap and watertight end seals, or
* Storm sewer pipe of water main material shall be
					 installed, or
* Reinforced concrete pipe storm sewers shall be
					 constructed with gaskets manufactured in accordance with ASTM
					 C443.