2013 Water System Plan, Volume II - Seattle City Clerk's Office - City ...

Chapter 5 Water Infrastructure
U.S. Environmental Protection Agency (EPA) to set national health-based standards for drinking
water to protect against both naturally-occurring and man-made contaminants.
5.4 BASIS OF DESIGN
For this DSG, basis-of-design documentation communicates design intent primarily to plan
reviewers and future users of a constructed facility. For SPU, this documentation consists
primarily of a basis-of-design plan sheet. By documenting the basis of design and archiving it
with project record drawings (as-builts), future staff will have easy access to design decisions.
5.4.1 Basis-of-Design Plan Sheet
The basis-of-design sheet is a general sheet that shows a plan overview and lists significant
design assumptions and requirements for major design elements (Figure 5-3). The following are
SPU standards for this sheet:
The design engineer must include a basis-of-design plan sheet in the plan set.
The sheet must be archived with the record drawings (as-builts).
Figure 5-3
Basis-of-Design Plan Sheet Data for Water Infrastructure
Basis-Of-Design Plan Sheet
WATER--------------------------------------------------------------------------------------------------------------
Type of Main (Transmission, Distribution, Feeder)
Design Flow Rate: ____________________
Flow Velocity: __________________________
Typical Pressure: _____________________ Pressure Zone(s):_______________________
Working Pressure: ____________________ Surge Pressure: ________________________
Pipe Materials:
______________________________________________________________________
(type, lining, coating, joints, pressure class minimum slope, buoyancy safety factor, minimum
cover [roads, non-roadway], deflection lag factor, construction tolerance, steel deflection limit)
Bedding Compaction:
______________________________________________________________________
(roadway, non-roadway, bedding constant, modulus of soil reaction [E’])
Appurtenances:
_______________________________________________________________________
(isolation valves, blow-offs/drains, line valves, air-vacuum and air-release valves, valve limit
settings for control valves, design criteria for all valves)
Access Ports:
_______________________________Datum:__________________________________
Basis of HVAC Design:______________________________________________________
Basis of Process Control:____________________________________________________
Project Specific/Special Information:
SPU Design Standards and Guidelines
5-13