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TiffinWater Treatment Plant

Comprehensive Facility Plan (Audit)

May 2016

Jim WeltyAqua Ohio

Jill Marie P.E.Rich Atoulikian P.E.

Glenn Dostal P.E.HDR

What is an Audit? Why are Audits Conducted? How are Audits Conducted?

Application at the Tiffin WTP:o Facility Overviewo Findings and Recommendationso Capital Planningo Key Considerations

Agenda

Comprehensive Review of the WTP:o Facility Inventory and Data Collectiono Condition Assessment:

• Performance• Condition• Reliability and Redundancy

o Develop Project Descriptions and Cost Estimates

o Prioritize Projectso Develop Capital Improvements

Program Conducted on a rotating 4 – 5 year

basis

What is an Audit?

Key Considerations:o Performance:

• Water Quality• Current and Future Water Demands• Current and Future Regulations• Approved Capacity Analysis

o Condition Assessmento Reliability and Redundancy

What is an Audit?

Comprehensive Facility Plan

Water Quality Current

Water Demands

FutureWater

Demands

Current Regulations

Future Regulations

Approved Capacity Analysis

Condition Assessment

Reliability

Redundancy

Capturing Key Knowledge Develop Capital Improvements Plan Operation Optimization Training New Employees Succession Planning

Why are Audits Conducted?

Interview Plant Personnelo Managemento Plant Operations Staff Review Historic Plant Data Visual Inspection of Plant Additional Quantitative Analysis,

as needed

How are Audits Conducted?

Five Levels of InspectionHow are Audits Conducted?

Level 5 Destructive

Forensic Testing

Level 4Non-destructive Forensic Testing

Level 3Performance Testing

Level 2Observation

Level 1Age

Tiffin

Single Team ApproachHow are Audits Conducted?

Process

Structural

Mechanical

Electrical

I&C and SCADA

ASMEC Form ExampleHow are Audits Conducted?

Process Form ExampleHow are Audits Conducted?

Aqua Standard Electrical and I&C Forms

How are Audits Conducted?

Condition Assessment RatingsHow are Audits Conducted?

Reliability Risk Assessment RatingsHow are Audits Conducted?

Performance Assessment RatingsHow are Audits Conducted?

Condition Assessment Decision Tree

Condition Assessment Framework

A well-defined asset inventory will facilitate project prioritization

Example – Tiffin WTP

Combined Surface and Groundwater Sourceso Sandusky Rivero 4 wells Average Daily Production Rate =

1.8 MGD Sole source of water for City of

Tiffin (no interconnections)

Facility Overview –General

Conventional Treatment:o Coagulationo Flocculationo Sedimentationo Multi-media filtration including

GACo Disinfectiono Fluoridationo Finished Water Storage

(with aeration system)

Facility Overview -Treatment Process

Primary and Secondary DisinfectionSodium

Hypochlorite• Applied Pre-Settling, Post-Settling (Intermediate), and Post-Filtration

CoagulationPoly-Aluminum Chloride (PACL)

To facilitate floc formation and algae removal in the Settling Basins during warmer months

Coagulant Aid (Polymer)

Taste and Odor ControlPowdered

Activated Carbon (PAC)

For dental care, as required by Ohio CodeHydrofluosilicic Acid (Fluoride)

Facility Overview

Sludge/Drain Pump Station

Filtered WaterTransfer Pumps

Mill Race

Wash Water Storage Tank

Raw and Finished Water Pumps

Settling Basin #2

Backwash Transfer Tank

Mixing Tank

Filters 1 - 3

Surface Water Intake Well

Settling Basin #1

Lagoon #1

Dried Sludgestockpile

Finished Water Clearwell

Lagoon #2

Head Gate & ScreenIntake Structure

Facility Overview

Historical Water Demands

Surface Water:o Turbidity

• 10 NTU to 2,500 NTU• Up to 7,000 NTU on occasion

o Algae Issueso High Nitrate Levels Groundwater:o High Strontium Levels Typical blend ratio:o 65% (surface) to 35% (groundwater)o Temperature adjustment

Water Quality Challenges

Key Existing SDWA RegulationsSurface Water Treatment Rule (SWTR)

Lead and Copper Rule and Revisions

Total Coliform Rule (TCR)

Interim Enhanced Surface Water Treatment Rule (IESWTR)

Stage 1 Disinfection Byproducts Rule (Stage 1 DBPR)

Filter Backwash Recycling Rule

Radionuclide Rule

Arsenic Rule

Stage 2 Disinfection Byproducts Rule (Stage 2 DBPR)

Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR)

Raw Water Turbidity

Settled and Filtered Water Turbidity

TTHM - LRAA

HAA - LRAA

Key Future RegulationsStrontium

Perchlorate

Long-Term Lead and Copper Rule (LT-LCR) Revisions

Carcinogenic VOCs (cVOCs)

Hexavalent Chromium

Nitrosamines

Chlorate

Flocculation (Mixing Tank) - Capacity

Component Number of Units Description Design Criteria Required /

Recommended

Component Capacity

(MGD)

Flow Basis of Component

(Capacity/Ratio)

Equivalent Max-Day Capacity

(MGD)

Flocculation(Mixing Tank) 1 28' dia. X 14' swd

Volume = 0.064 MGDetention time ≥ 30

minutes Recommended 3.10 MGD - -

Center feed radial flow tank

Sedimentation - Capacity

Component Numberof Units Description Design Criteria Required /

Recommended

Component Capacity

(MGD)

Flow Basis of Component

(Capacity/Ratio)

Equivalent Max-Day Capacity

(MGD)

Sedimentation 2

Settling Basin #1: L = 79.50', W = 44.67‘

SWD = 11.50') Volume = 0.305 MG

HDT ≥ 4 hours Required 1.83 MGD max day 1.0 1.83 MGD

WOR ≤ 20,000 gpd/ft Required Not Applicable

Surface Loading Rate ≤ 0.5 gpm/ft2 Recommended 2.56 MGD - -

Settling Basin #2: Dia = 75‘

SWD = 11' Volume = 0.364 MG

HDT ≥ 4 hours Required 2.18 MGD max day 1.0

2.18 MGD

WOR ≤ 20,000 gpd/ft Required Not Applicable

Surface Loading Rate ≤ 0.5 gpm/ft2 Recommended 3.18 MGD - -

Sedimentation Total: 4.01 MGD

Settling Basin #1 – End feed rectangular basin with submerged discharge orifice cones at opposite end. Settling Basin #2 – Peripheral feed spiral flow basin with discharge point located at the center of the tank.

Filters - Capacity

Component Number of Units Description Design Criteria Required /

Recommended

Component Capacity

(MGD)

Flow Basis of Component

(Capacity/Ratio)

Equivalent Max-Day Capacity

(MGD)

Filters 3

Filters #1 and #2: 22' x 12' each

Area = 264 ft2 each

Filter #3: 21'-10" x 12'-2" Area = 266 ft2

Total Filter Area = 794 ft2

Max-Day (with largest unit out-of-service);

Filtration Rate less than or equal to 4

gpm/ft2

Required 3.04 MGD max day 1.0 3.04 MGD

160 hours run time between backwashes. Less than 24 hours without pre-chlorination. Free chlorine residual in the settling basins and

to the filter tops are kept as low as possible to address algae issue, but minimize formation of DBPs.

Clearwell - Capacity

Assumptions:Max CT value = 41 mg/L-min: min Cl2 = 1.64 mg/L, max pH > 8 min temperature = 5 deg-C

Component Number of Units Description Design Criteria Required /

Recommended

Component Capacity

(MGD)

Flow Basis of Component

(Capacity/Ratio)

Equivalent Max-Day Capacity

(MGD)

Cleawell 1 (with 2 cells)

Cell #1: 0.274 MG @ 10' swd

Cell #2: 0.287 MG @ 10' swd

Total: 0.561 MG @ 10' swd

Max CT req'd for 0.5-log Giardia inactivation = 41 mg/L x min

Required 16.21 MGDpeak hour treatment

1.1713.85 MGD

Recommendations Source Water:

Major Component Recommendation Priority

Groundwater Wells

Retain services of a Hydrogeologist to study well production rate trends to understand the reliability of the capacity of the existing wells. 1

Install additional production well. 1Conduct SWIP and MPA testing to determine whether or not the well sources are actually under the influence of surface water. 1

Based upon the results of the SWIP and MPA testing, consider a contingency plan which involves placing infrastructure to allow supply of well water directly to either the Filters or the Clearwell for additional reliability.

2

Major Component Recommendation Priority

Mixing Tank

Repair all moderate to severe deterioration along the concrete foundation at the base of the tank and minor tank corrosion.

1

Consider replacing existing tank and adding a second tank. 1 - 2

Recommendations Mixing Tank:

Major Component Recommendation Priority

Settling Basin #1

Replace wooden baffles with FRP. 2

Complete all necessary repair work recommended in May 2011 Tank Inspection Report.

2

Replace WEDA sludge removal system. 3

Settling Basin #2

Complete all necessary repair work recommended in May 2011 Tank Inspection Report.

2

Install a baffle with scum removal trough to facilitate removal of floating material.

1

Replace WEDA sludge removal system. 3

Recommendations Settling Basins:

Recommendations

Major Component Recommendation Priority

Filtered Water Transfer Pumps

Install a third pump to increase redundancy capacity and improve reliability.

1

Replace two existing pumps prior to reaching the end of their useful life. 2

Filters and Filtered Water Transfer Pumps:

Major Component Recommendation Priority

Fini

shed

Wat

er

Clearwell

Monitor and Repair minor damage caused by wildlife to the protective structural panel façade of the clearwell tank.

2

Aeration System Continue Operation -

High Service Pumping

Change out Pump #13 to a vertical arrangement similar to Pumps #15, #16, and #17.

2

Equip Pumps #13 and #16 with a VFD. 1

Recommendations Clearwell and Finished Water:

Other Process Recommendations

ProcessConcern Recommendation Priority

Strontium Removal

Possible Cation Exchange System. Perform treatment technology analysis to confirm the best treatment option for strontium. 2

Algae Speciation

Purchase testing equipment and complete algae speciation to determine the impact that potential algae toxin regulations may have at this facility (complete each season).

1

Algae control and DBP reduction

Conduct additional studies to evaluate the alternatives of chlorine dioxide or dissolved air flotation for algae control. Chlorine dioxide as a pre-oxidant would also help reduce DBP formation.

1

Recommendations Structural:o Repair and seal cracks, repair

spalled concrete, address areas with minor corrosion.

o Analyze buckled bracing at retaining walls along the Mill Race Channel.

o Flood Panel - Flood Log - stop gate system for all at risk doors.

Recommendations Electrical:oSingle point failures that could result in prolonged interruption of the WTP

operation.• (Active and standby pumps connected to same MCC)

oCritical facilities have back-up power supply. • (Aeration System and Wells)

Mechanical (HVAC):oProper ventilation in accordance with code requirements.

Capital Planning

Plan your attack Take experienced teamo Code issues are a big factor Meet with plant staff to obtain history,

records, and reports Team up with applicable owner

discipline during site visit Take pictures, take more pictures Summarize results and complete

estimate ASAP Plan for the future Develop initial project priorities, then

review, adjust and finalize with Owner

Key Considerations

Questions