What Road Designers Need to Know about AWWU Design and Construction Standards

1. What Road Designers Need to Know about AWWU Design and Construction Standards Presentation to: ADOT&PF Quarterly Design Meeting October 8, 2013

2. The Top 10 List for Road Projects • Separation Distance Requirements • Standard Materials • Cut/Fill Impacts • A.C. Pipe Considerations • Hydrant Relocation Considerations • ROW Acquisition/Building Demo • Pipe Relocations • Water Outage and Temporary Water Requirements • Service Extensions • AWWU Information Available

3. Recommended Separation Distances – Why does AWWU have them? Regulatory Requirements • Minimum 10-foot Horizontal (measured outside of pipe to outside of pipe) between water and either sanitary sewer or storm • Minimum 18-inches of vertical separation • ADEC Separation Distance Waiver • Maintenance Requirements • 15-feet from Power Pole or Transformer Pad • 10-feet from light poles, electrical/telephone/cable boxes

4. Separation distance requirements are not only for regulatory requirements, but also for constructability and protection of facilities from freeze conditions.

5. With this Oil Grit Separator Installation, construction near 30-inch WTM has both Regulatory and maintenance concerns.

6. Standard Materials – Concerns • Consistency of System • Not all things are created “equal” • Cathodic Protection • Not required for PVC or HDPE • Metallic Pipe in Groundwater – Tightly Bonded coating and CP • Metallic Pipe not in Groundwater – PE barrier and anodes • Required on Sewer mains as well

7. Standard Materials -Continued • Hydrants – Mueller and American Darling • Pipe: • PVC – C900/C905 for Water and Sewer • HDPE – C906, Outside Diameter Conforming to IPS • Ductile – Class 50 for Sewer, Class 52 for Water • Detectable Warning Tape Required for all types

8. Cut/Fill Impacts • Water • Standard Burial Depth is 10-feet • Insulate if shallower • Generally, no shallower than 6-feet and only for limited distances • Sewer • Standard Burial Depth is 8-feet • 5 ½ feet without insulation • 4 ½ feet with insulation (Not allowed for force mains)

9. Cut/Fill Impacts Continued • Special Ditches • Impacts to Services Often Overlooked • Maintenance Requirements • Generally, no deeper than 15-feet • Service Lines, no deeper than 12-feet • What is future impact if we have to dig • Pipe Material Considerations • What is maximum burial depth for given material?

11. Extreme Case: Glenn-Bragaw Interchange 42-inch RCCP had design burial depth of only 12-feet to TOP Rather than relocate, encased

12. A.C. Pipe Considerations • Non Corrosive Material – But “Fragile” • Water Mains • Short sections of pipe – joint shifts • Excavations adjacent can undermine pipe • Mass Excavation of Road Prism–Temporary Reduction of Burial Depth • Increased loading and vibratory impacts • Cracks/Collapse of Sewer Mains have occurred

13. Relocating a Hydrant – More Involved than you Might Think • Water outage usually required • Yes, we want the old valve removed • 15-feet from any water or sewer service • Need for easement behind the hydrant • 5-foot by 10-foot – Centered on Hydrant

15. ROW Acquisition and Building Demo – I have to dig where? • Building Demolitions Require service to be properly disconnected • Water requires disconnect at the main. • “Rolling” the copper is not permanent • Sewer requires disconnect and plugging at the property line. • If property is going to become ROW disconnect at the main.

16. Pipe Relocations • Needed for conflict resolution and separation distance requirements • Water can be rerouted “easily” • Water Outage and/or Temporary Water Systems • Potentially more expensive than avoidance • No 3-Part Unions for Water Services • Sewer is hard to relocate and avoidance should be primary method for dealing with conflicts • Sewer Services

19. Water Outage and Temporary Water Requirements • Outage Areas can be large for “small” item of work • Public Outreach needed • Restaurants and other Food Service Establishments – 3 hours • No more than 6-hours in a 24-hour period • We tend to stretch this a lot with water line lowering • Performance Metric for AWWU

20. Water Outage and Temporary Water Requirements • Temporary Water Systems should be specified and connection information for commercial buildings provided • Cost of temporary water system can be as much as pipe installation: • Requires testing and disinfection • Backflow preventers and certifications • Excavations to install and can be complex connections

22. Service Extensions – Why not to Build them! • Do not build a connection unless a property owner requests it. • Can sit unconnected for many years • Potential freeze and break scenario – AWWU maintenance headache • Infiltration point for sewer services • Not in “right” location for future development • Who pays for it? • If you build one, follow location rules.

23. Information Available • 300 Scales • Not always correct, but a good start!!!! • Record Drawings • Beware Datum Elevations • Connect Cards for Services • CCTV • Existing condition of mains • Verify sewer service stub locations • Can help with storm/fin drain design planning

25. When in Doubt – Just Ask JOE!!!! • Joe Sanks joe.sanks@awwu.biz 564-2717 • Stephen Nuss, P.E. stephen.nuss@awwu.biz 564-2763