unofficial informal business discussion minutes tuesday ......nov 03, 2015 · tuesday, november 3,...
TRANSCRIPT
Unofficial Informal Business Discussion Minutes Tuesday, November 3, 2015 – 3:00 PM
Present: Charlotte J. Nash, Jace Brooks, Lynette Howard, John Heard, Tommy Hunter
1. Water Resources Pipe Standards Discussion Department of Water Resources’ Director Ron Seibenhener presented proposed revisions to Gwinnett County’s Water, Sewer and Stormwater Pipe Standards. No Official Action Taken.
WATER RESOURCES
Proposed Revisions Water, Sewer and Stormwater
Pipe Standards
November 3, 2015
Mission and Vision
To Provide Superior Water Service at an Excellent Value
To be widely recognized as a leader in the water industry
Tenets Support our Mission
Continuous Improvement
Superior Asset Management
The Right Asset In the Right Place
Installed in the Right Way
Replacement Value of our Assets
Water Production Facilities
Water Reclamation Facilities
Distribution System
Collection System
Stormwater System
$0.5 Billion
$1.3 Billion
$2.6 Billion
$2.3 Billion
$3.0 Billion
Asset Management Levels
Water & SewerFacilities
Water & SewerPipes
Stormwater Pipe
Providing Fundamental
Services
Optimizing Operations and
Services
Utility of the Future
Objectives of the Revisions to Pipe Standards
Correct Errors
• Governing Standards • Industry Standards • Manufacturer’s Recommendations
Provide Clarity
Between
Include New Industry
Improvements
Streamline & Simplify
WATER RESOURCES
Proposed Revisions to the Water Main and Sanitary Sewer Standards and Specifications
Document Review
Water Systems
Water Pollution Control
87 Pages
2 Volumes: 163 Pages Combined
76 Pages
Proposed: One Document
Gwinnett County Water Resources
1 Volume: 115 Pages Total Savings of 48 Pages
Example Pipe Installation Diagram
Pipe Zone
Final Backfill
Pipe
Bedding
Initial Backfill
Road Detail
Water and Sewer Pipe Material Pipe Material dictated by Location and Use
Pipe Material Application DIP
(Water Mains)
All Water Mains less than or equal to 64” in diameter*
DIP (Gravity Sewer)
Any Gravity Sewer*
PVC (Gravity Sewer)
Gravity Sewer, when Pipe ≤ 24 inch in diameter and < 16 feet of cover
*Greater than 64” in diameter is a custom design
Water and Sewer Pipe Pipe Zone Requirements based on Pipe Material & Use
Pipe Zone Pipe
Bedding
Initial Backfill
Water and Sewer Pipe Pipe Zone Requirements based on Pipe Material & Use
PVC Gravity Sewer DIP Water Main DIP Gravity Sewer
Pipe Installation – Final Backfill Final Backfill based on Location
Location W&S
Final Backfill Requirement
Shoulder and Under
Pavement* 95% compaction
Outside Pavement in
ROW 90% compaction
Outside of ROW 85% compaction
(unless directed by Engineer)
* Under pavement means all or part of trench is under pavement
Final Backfill
Pipe
Three Problem Areas Identified
Sewer Service Laterals
Pipe Material Transitions
New Development Sewer Connection
1. Sewer Service Lateral 6” County Stub to 4” House Connection
Current New
Pipe Material Transition Ductile Iron to PVC Connection
Current New
2.
Sewer Connection New Development to Existing Sewer
Current New
3.
Sewer Connection New Development to Existing Sewer 3.
Manhole with Plugs and Locking Cover
Mechanical Screw (Wing Nut) Plug
Locking Manhole Cover
W&S Pipe Installation Quality Assurance
Ensuring Qualified Contractors
•Approved contractor list •Construction permits required
Testing During Construction
•Developer tests with County verification •Bedding Materials •Compaction
Inspections Prior to Acceptance •Pressure Tests (Contractor, County verify) •Disinfection of Water Lines (Contractor, County verify) •CCTV, Mandrel, Laser Profiling (County)
WATER RESOURCES
Proposed Revisions to the Stormwater Systems and Facilities
Installation Standards and Specifications
Asset Management Levels
Water & SewerFacilities
Water & SewerPipes
Stormwater Pipe
Providing Fundamental
Services
Optimizing Operations and
Services
Utility of the Future
Why Such a Low Bar for Stormwater Pipe?
The General View Is
• “It’s just drainage”
The Correct View Is
• It’s a $3 Billion Asset • It’s aging and failing creating a
tremendous liability • It’s under funded • Our standards, specifications and
installation practices do not support its value
Stormwater Pipe Risk Levels, Impacts and Locations
Risk Level Impacts Locations
Many people
Structures
Major Roads
Local Roads Public Access
ROW
Few people
Under pavement of major roads
Passing water from development to development Passing water between public ROW and private property In close proximity to structure Carries a perennial stream
Under pavement of local road
Longitudinal (along roadway)
Under driveways
Lateral (not near structure)
Medium Consequence
of Failure
High Consequence
of Failure
Low Consequence
of Failure
Stormwater Pipe Materials & Pipe Zone Detail Dictated by Location
Location Pipe Material Pipe Zone Detail
Under pavement of major roads RCP High Risk
Passing water from development to development RCP High Risk
Passing water between public ROW and private property RCP High Risk
In close proximity to structure RCP or HPDE High Risk
Carries a perennial stream RCP or HPDE High Risk
Under pavement of local Roads All 3 Materials High Risk
Drainage off roads All 3 Materials High Risk
Under driveways All 3 Materials Low Risk
Laterals (not near structures) All 3 Materials Low Risk
Pipe Material By Location Major (non-local) Roads
Pipe Material by Locations Local (S/D) Roads
Stormwater Pipe Materials & Pipe Zone Detail Dictated by Location
Location Pipe Material Pipe Zone Detail
Under pavement of major roads RCP High Risk
Passing water from development to development RCP High Risk
Passing water between public ROW and private property RCP High Risk
In close proximity to structure RCP or HPDE High Risk
Carries a perennial stream RCP or HPDE High Risk
Under pavement of local Roads All 3 Materials High Risk
Drainage off roads All 3 Materials High Risk
Under driveways All 3 Materials Low Risk
Laterals (not near structures) All 3 Materials Low Risk
Stormwater Pipe Pipe Zone Requirements based on Pipe Material & Risk
Reinforced Concrete Pipe
Higher Risk Locations Lower Risk Locations
Stormwater Pipe Pipe Zone Requirements based on Pipe Material & Risk
Aluminized Steel Pipe
Higher Risk Locations Lower Risk Locations
Stormwater Pipe Pipe Zone Requirements based on Pipe Material & Risk
High Density Polyethylene Pipe
Higher Risk Locations Lower Risk Locations
Pipe Installation – Final Backfill Consistent with W&S and GCDOT Requirements
Location
W&S Final Backfill Requirement
Stormwater Final Backfill Requirement
Shoulder and Under
Pavement*
95% compaction
95% compaction
Outside Pavement in
ROW
90% compaction
90% compaction
Outside of ROW
85% compaction
unless directed by Engineer
85% compaction
unless directed by Engineer
* Under pavement means all or part of trench is under pavement
Final Backfill
Pipe
Stormwater Pipe Installation Quality Assurance
Ensuring Qualified Contractors
•Approved contractor list •Construction permits required
Testing Before Design
•Developer tests with County verification •pH and resistivity (ASP only)
Testing Before and During Construction •Developer tests with County verification •Bedding Materials •Compaction
Inspections Prior to Acceptance •County does inspections •CCTV, Mandrel, Laser Profiling
Asset Management Levels
Water & SewerFacilities
Water & SewerPipes
Stormwater Pipe
Providing Fundamental
Services
Optimizing Operations and
Services
Utility of the Future
Asset Management Levels
Water & SewerFacilities
Water & SewerPipes
Stormwater Pipe
Providing Fundamental
Services
Optimizing Operations and
Services
Utility of the Future
Questions?