water supply and treatment evaluations and improvements

Water Supply and Treatment Evaluations and

Improvements

June 8, 2016

Maintain High WQ

Meet Growth Potential

Protect Water Source

Improve Treatment

Extend Facility Life

Implement Improvements

Project Goals

Evaluation & Implementation Approach

Desktop Study

Preliminary Design

Final Design Bid Phase Construction

Desktop Study - Step-Wise Strategy

Identify Problems

Develop Solutions

Evaluate Solutions

Determine Phased

Path Forward

Scope of Work for Desktop Study

►Demand Reassessment

►Data Review

►Well Field:

• Well capacity

• Firm yield

• Condition assessment

• Measures to control

contamination

►WTP:

• Process evaluation

• Filter evaluation

• Finished water stability

• Regulatory review

• Condition assessment

• Schematic design

• Alternatives evaluation

• Opinion of probable cost

►Report

5

Existing System Capacity

Wells

• 5 active

• 1 inactive

• Up to 3 MGD each

Demand

• Max Day = 5.0 MGD

Result

• Run 2 wells to meet Max Day

Well Field Evaluations

Observations

► Specific capacity decline of all wells is normal

• Current specific capacities is still high (100 gpm/ft or more)

► Wells 2A, 4A, and 7 fall into the Design Life category

• These wells can still maintain their design pumping rate

► Well 5 and 6 are into the Life Expectancy category

• Well 6 has been lined due to a structural failure in the casing

• Well 5 is almost 50 years old and has a low specific capacity

► Reliance on Well 6 (pumped almost every day) is a

concern given structural failure

► Model compares very favorably to

real world plume migration

► Well 1A contains ammonia/nitrogen

plume

• 600 gpm

• Capture zone is approximately 1700

feet wide

USGS Model Results

Contaminant Sources and Well Field Contributing Recharge Area

The vast majority of potential contaminant sources are hydraulically

downgradient of your well field

NKC Well Field Contributing Recharge Area

Presence of Lead► 20 Shallow Soil Samples

• One soil sample above MDNR

Residential Target Level (260

mg/kg)

• All below MDNR Non-

Residential Target Level

►Not in Aquifer• ND in 14 groundwater samples

(2009)

► Lead in Soil is Not Mobile

• Only mobile in acidic soils

• Soil pH 7.5 to 10.8 (2009)

► No Data to Support Lead

Contamination of Well Field

1 1

► Update USGS model and update with current well field conditions

• Confirm capture zone

► Operate Well 1 to contain ammonia/nitrate

• Run at 600 gpm

• Breakpoint chlorinate ½ of flow

Well Field Recommendations

Downhole TV Survey –Integrity1

Rehab Well / New 600 gpm

Pump

Depth Related WQ Samples

1If Well 1A has a structural problem, redrill well

Well Field Recommendations

►Add emergency backup

power to South wells

►Redrill Well 6

►Redrill Well 5

►New valve vault for

remaining wells

►Firm capacity will be12

MGD

WTP Evaluations

► Issues:• Electrical System

• SCADA/Control System

• Hydraulic Issues

• Structural / Mechanical /

Architectural Issues

• Chemical Utilization / Feed

• Settled Water Turbidity

• High Service Pump Issues

A Partial Rehabilitation is Recommended!

Treatment Goals

► Hardness removal

► Raw water quality

• Ammonia

• Nitrates / Nitrites

• TOC and VOC

► Disinfection Byproducts

► Future regulatory requirements

• GWUDI Compliance

• Emerging Contaminants

Aerator and Optional Bypass

`

Wells

Upflow Solids Contact Clarifier

(North)


(South)

Dual Media Filters

Clearwell

High Service Pump Station

Chlorine

Carbon Dioxide

To Distribution System

PrimaryCO2 Recarb

Basin

Raw Water Parameter Sampling

Finished Water Continuous Online Total and Free

Chlorine Measurement

Lime

Optional Bypass for Primary and Secondary Clarifiers

Lime

SecondaryCO2 Recarb

Basin

Phosphate


StabilizationBasin

Existing Process Schematic

Chlorine

Aerator and Optional Bypass

`

Wells


(North)


(South)

Dual Media Filters

Clearwell

High Service Pump Station

Chlorine

Carbon Dioxide


CO2 RecarbPiping

Raw Water Parameter Sampling

Finished Water Continuous Online Total and Free

Chlorine Measurement

Lime

Optional Bypass for Primary and Secondary Clarifiers

Lime

Phosphate


StabilizationBasin

Proposed Process Schematic

Chlorine

Well 1 with Breakpoint Chlorination

Chlorine

Evaluations / Observations

► Transformers Service/Parts Issues

► MCCs Service/Parts Issues

► No Pump Local Disconnects

► Genset Configuration – Code

► No South WF Genset

► SCADA Outdated/Lacks Capacity

► Instrument Upgrades

Recommended

Recommendations

► New Pad Mounted Transformer

► New Motor Control Centers

► Add Pump Disconnects – Code

► Reconfigure Ex. Genset

► Add South WF Genset

► New SCADA

► New Instrumentation

Electrical / SCADA


► Ex. Chlorine gas system

► Code/Safety Issues – no scrubber

► Under-capacity

► Evaluated:

• Gas

• Bulk hypochlorite

• On-site generation

• Comparable 20 year present values

Recommendations

► Ton Container Gas System

► Dry Scrubber

► Use 4000-5000 #/month (avg)

Disinfection (Chlorination)


► Iron Build-up

► Access

Recommendations

► Replace Internals

► Add Catwalks

Aerator


► Corrosion on launders and scrapers

► Some corrosion on other

components

Recommendations

► Replace launders and scrapers

► Re-coat basin equipment

Softening Basins


► Basins Not Required

► Building Structural Issues

Recommendations

► Remove Building

► Demo Basins

► Replace Basins with Piping

► Rebuild Space for Proposed

Electrical/Chemical Building

Recarbonation


► Backwash flow calibration is

excellent

► Size-matching of sand and

anthracite is good

► Media bed expansion lower than

recommended

► Backwash length shows diminishing

returns

► Top layer of media slightly dirty after

backwash

Recommendations

► No changes recommended for

additional benefit at current capacity

and operating conditions

► Add 2” anthracite

Filter Evaluation


► Replace Two Pumps

► Replace One Impeller

► Meters Placement Poor

► Raw Meter Out of Calibration

Recommendations

► Replace Pumps 3 & 4

► Replace Impeller in Pump 1

► Add VFDs for Improved Control

► Add Two New Meter Vaults

► Replace Raw Meter

High Service Pumping / Metering


► Filter Roof Leaks

► Filter Flooring Needs Replaced /

Asbestos

► Rotting Drywall and Ceiling Tiles

► Peeling Lead Paint in Operable

Parts of WTP

► Admin Area Miscellaneous Issues

Recommendations

► Re-Roof Filter Gallery

► Replace Filter Epoxy Floor

► Remove Rotting Drywall and Ceiling

Tiles – No Replacement

► Remove Lead Paint

► Renovate Admin Area

Architectural


► Structural Supports for Morton

Buildings – Wood Rot

► Miscellaneous Concrete and

Masonry Repairs Required

► Access and Safety Thru Plant

► Poor Loading Dock Access

Recommendations

► Replace Columns for Softening

Basins and Demo Recarb Basins

► Repair Concrete and Masonry

► Add Catwalks and Handrail – Code

► Extend Loading Dock 12’

Structural


► Make-up Air Units, Air Supply and

Exhaust Fans Life Exceed

• Basement

• Admin Area

• Solids Contact Basin Area

• Filter Gallery

► Hot Water Heater – Life Exceeded

Recommendations

► Replace Make-up Air, Air Supply and

Exhaust Fans

► Replace Hot Water Heater

Mechanical


► Two units

► Require attention / maintenance

► Not able to achieve optimal conditions• Temperature

• Water/lime ratio

• Reaction time

Recommendations

► New equipment will reduce lime use

10%

► New lime equipment is priority 2

Lime Slaking

Residuals

Continued

Discharge to

Missouri River► MDNR Coordination

• Anti-Degradation Study

• Professional Judgment Analysis

► Solids Loading <= Current

► No Visible Discharge in River

Residuals

Continued Discharge to Missouri River

► Surge Basin / Dilution

► Dechlorination /

Metering

► Connect to existing

outfall system

► Other Alternatives

Figure 7-1: Proposed Chlorine Gas Location and

Layout (Ton Cylinders)

M

M

M

SCRUBBER

ELECTRICAL

EQUIPMENT AND

BREAKPOINT PIPING

FEED ROOM

STORAGE

ROOM

TRANSFORMER GENERATOR

3 2

Opinion of Probable CostItem Cost Priority 1 Priority 2

Well 1 240,000 240,000

Well 6 580,000 580,000

Chlorine (WTP + Breakpoint): 2,000,000 2,000,000

CO2 610,000 610,000

Aerator 300,000 300,000

Solids Contact Basins 463,000 463,000

Filter Media 80,000 80,000

Filter Valves 670,000 670,000

High Service Pump Station / Meter

Vault / Raw Water Meter 1,130,000 1,130,000

Chemical Changes 190,000 190,000

Electrical - WTP & N. Well Field 1,400,000 1,400,000

Electrical - S. Well Field 560,000 560,000

Structural 1,690,000 1,690,000

Architectural 1,040,000 1,040,000

Mechanical 1,190,000 1,190,000

Civil 140,000 140,000

Well 5 760,000 760,000

Well 2A, 4 & 7 Vault Improvements 590,000 590,000

Lime: 3,590,000 3,590,000

Total 17,223,000 13,633,000 3,590,000

Next Step – Preliminary Design

Funding AgreementComplete within 6 months

Final Design Bid PhaseConstruction

Phase

Jeff [email protected]

816-822-3438

mailto:[email protected]

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