. EXAMPLES FROM THE DEMONSTRATION PROJECTS
The city of Lacey requires a 10-foot separation between public water and public sewer, a state and local code provision. When a sewer lateral crosses a water main or vice-versa, a З-foot vertical separation must be maintained. This occurred in The Park, but Phillips was unable to make the З-foot vertical separation.
Because of this, the city required a heavy gauge metal sleeve around the water pipe within 10 feet of the sewer. This apparently is a carryover requirement from the time of cast iron and concrete soil pipe, when joints often broke and leaked. However, with longer lengths of seamless PVC pipe available, the separation requirements and the need for a metal sleeve appear to be unnecessary.
Builders in Portland frequently install gas, electric, telephone, and TV lines in a common trench. In addition to allowing this practice, the city of Portland permitted Robinson to install his common trench and water line trench outside the right-of-way. The city also allowed the use of less expensive native backfill instead of off-site granular backfill. The city would not waive their normal requirement that sanitary sewer mains be placed in a separate trench in the right-of-way. Robinson saved $5,040 by installing his common trench and water line trench outside the right-of – way and using backfill from the site.