Admin Order 58-16-01 - Laserfiche WebLink

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5. Ultimate service area boundaries (from Wastewater Master Plan and consultation with the City). 6. Sub -service area boundaries, each individually highlighted in some way. 7. Legend details such as, but not limited to, north arrow and scale. 8. Company name, designer's name, and date. 9. Demonstration that all buildable areas within the development can be served. B. Design Approach Wastewater service shall be extended in conformance with the approved waste water basin master plans. Public mains shall be extended at minimum slope unless an engineering study demonstrates the basin can be adequately served by steeper grades or shallower mains. Wastewater mains shall be extended to the limits of the development served for the purpose of future extension unless an engineering study demonstrates service is already available or an alternate service route is more efficient. The minimum pipe diameter for wastewater mainline is 8 inches. 6 -inch pipe may be used on residential mainlines in the most upstream reach, if the length of the reach is less than 250 feet and if no more than 4 single dwellings are served. The minimum desirable slope for a 6 -inch mainline system is 1 percent and for an 8 -inch mainline system is 0.40 percent. The minimum desirable cover is 5 feet at the extreme upstream manhole in a service area; additional cover requirements may apply. The maximum desirable design flow depth is 80 percent full. The minimum design velocity is 2 fps. Notwithstanding minimum design velocity, the City may approve the following adjustment: 8 -inch pipe slopes may be flatter than 0.40 percent only if necessary to maintain flow line depths to serve all lots in the service area. 8 -inch pipe slopes may be steeper than 0.40 percent where maintaining flow line depth is not, a design control. Where the system is not intended to be extended in the future, the slope of the last segments should be between 1 percent and 5 percent to achieve cleansing velocities. C. Manholes 1. Pipe Grades and Channel Slope Manholes shall be designed to minimize head loss through the structure. The crown Public Improvement Design Standards Manual, 2016 Page 2-45