Unofficial Informal Business Discussion Minutes Tuesday ......Nov 03, 2015  · Tuesday, November 3,...

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?