THE WONDERFUL WORLD OF

WATER

Steve Turner, P.E., PMP, ENV SP

Bite of Science

October 25, 2017

WHO AM I?

Steve Turner, P.E., PMP, ENV SP

• Project Manager – Gannett Fleming

• Husband and Father

• Volunteer

– Church

– Soccer

– K-12 Outreach

A Local Boy

Mary Atkins

Riverside Elementary

Dunbar Erwin Middle

Hines Middle

Ferguson High

Virginia Tech

Gannett Fleming

Gannett Fleming Background

• More than 60 offices worldwide

• 2,000+ professionals

• Diverse range of services and

specialized expertise

#11 – Top 15 in Dams & Reservoirs

#20 – Top 20 in Water Treatment and

Desalination

#19 – Top 25 in Wastewater

Treatment Plants

#26 – Top 50 in Water Supply

What Do I Do?

Three Major Elements of the Water Industry

Drinking Water

Three Major Elements of the Water Industry

Wastewater

What Do I Do?

Three Major Elements of the Water Industry

Stormwater

What Do I Do?

Potable Water Storage Tanks

Design

(5 KG to 20 MG)

Construction/

Coating

Inspection

Assessment

and Rehab Modifications Demolition

• Steel

• Composite

• Concrete

• Mixing Systems

• Antenna

Installation

• Instrumentation

• Chemical Feed

Tanks come in different shapes and sizes

Evaluating Candidate Sites (Dale City, VA)

Example Site Selection Criteria

• Set-back Requirements

• Site Size Requirements and Ownership

• Tank Operational Requirements

• Water Main Piping Requirements, Including the Distance to the Nearest Main and Approximate Cost

• Traffic Constraints/Impacts

• FAA Requirements/Height Restrictions

• Publicly Sensitive Areas (i.e. Historic and Archaeological)

• Utilities and Communication Requirements

• Environmentally Sensitive Areas including Site Visit

• Environmental Impacts (i.e. overflows)

• Wetlands, Streams and Floodplain Impacts

• Topography

• Soils

• Land Use

• Impacts on Water Age and associated Water Quality Changes

Lewisburg, PA Photo Rendering

Shadow Projections

Provide Construction Plans for Contractors

RECENT RELEVANT RESEARCH

They are compounds formed when chlorine reacts with naturally-occurring organic matter.

•Trihalomethanes (TTHM) •Haloacetic Acids (HAA) Currently Regulated

Understanding DBPs

HOCl + NOM Chlorinated Organics

Function of:

NOM Conc., Chlorine Dose, pH, temperature, time

Opportunities for Control

(TTHM and HAA)

Options for DBP Control in the Distribution System Piping Network

Flushing

Looping

Chlorination

Strategic booster chlorination

Storage Tanks

Operational adjustments

Tank mixing

Tank aeration

Storage Tank Options – Operational Adjustments

Estimated Water Age >> 16 days (Fluoride Tracer)

TTHM = 140 - 170 ppb

HAA = 80 – 95 ppb

Projected Water Age Following Operational Changes ~ 7 days

TTHM < 60 ppb

HAA < 50 ppb

Storage Tank Options - Tank Mixing Mixing equalizes water

age, temperature, and DBP concentration

Does NOT reduce DBPs

Still need water turnover to be effective

Two types:

Passive

Active

Image courtesy of PAX Water Technologies

Tank Mixing – Temperature Model 2 Minutes 30 Minutes 60 Minutes

Source: “The Science of Mixing Water Storage Tanks.” Michael J. Duer, P.E., 2003

Storage Tank Options - Tank Aeration

Aeration Theory

Aeration = exchange of gas from water to air

Governed by Henry’s Law [p = (HC) / (PT)]

TTHMs are VOCs, HAAs are Not VOCs

Storage Tank Options - Tank Aeration

Aeration Methods

Multiple Tray

Cascade

Packed Tower

Spray

Surface Aeration

Diffused Tray

NOT COST

EFFECTIVE

Storage Tank Options - Tank Aeration

Image courtesy of SolarBee

Storage Tank Options - Tank Cleaning Eliminates organic

matter that settles in storage tank

Identify issues during tank and coating inspections

Recommended every 3-5 years

Robotic options available without draining tank

EMERGING TECHNOLOGY

ROBOTICS

A Robot Invasion!?

WHY ROBOTS?

Two Primary Drivers

• Safety – inherent risk in climbing and entering storage tanks

• Efficiency – save money; save time

VIDEO SAMPLE OF DRONE INSPECTION

SUBMERSIBLE REMOTELY OPERATED VEHICLES (ROVs)

Internal Tank Inspection

• Advantages

– No tank entry required

– Performed while tank is still in service

– Multiple inspections per day (typical)

• Disadvantages

– Limited by water depth

– Roof assessment can be limited

– Sediment can obscure the floor

ROV VIDEO OF A CORRODED ROOF

AFTER REMOVING CORROSION PRODUCT TO EXPOSE METAL LOSS

ROV ADJUSTS LIGHTING FOR BEST VIEW

ROBOTIC STORAGE TANK CLEANING

Advantages

• Performed while tank is in service

• Cost-effective for sediment depths less than 1 inch

Disadvantages

• Time-consuming for sediment depths greater than 1 inch

• Limited by length of tether and hose for elevated tanks

Considerations

• Handling of effluent

– Filtration

– De-chlorination

• Sediment Disposal

VIDEO SHOWING POINT OF VIEW OF ROBOVACTM

VIDEO SHOWING SIGNIFICANT SEDIMENT DEPTH

TANK CLIMBING

• Manufactured by International Climbing Machines

• Held to surface by vacuum pressure

• Flexible seal adjusts to surface irregularities

• Weight = 23 lbs

• Speed = 2.7 in/sec

TANK CLIMBING – DRY FILM THICKNESS READINGS

• Positector and camera mounted to climber

• Gears enable lateral movement of Positector

TANK CLIMBING – WELD GRINDING

Animation of Proposed Unit

SHOP TESTING OF GRINDER

VIDEO OF SHOP TESTING

GETTING STUDENTS

INVOLVED

Classroom Presentations – Elementary/Middle

Classroom Presentations – High School

Model Water Tower Competition

• Free event

• Middle School

students build

functioning

water towers

• Every October at

ODU

Junior Water JAM

• Students tour Exhibit Hall and see latest technology

• Every September

• Annual Industry Conference

• Students Engage with professionals

Opportunities for Students

• Internships/Mentoring

– Private

– Public

• Hampton Roads

Public Works

Academy

• Treatment Plant or Laboratory Tours

Conclusions

Engineering…..

• Finding the best solution in a world full of

“right” answers

The Quest for “None of the Above”

THANK YOU!

QUESTIONS?