John Jay L. Swift, P.E

John P. Wilson, P.E. Arn G. Coombs, P.E. Jay L. Swift, P.E.

Pete Tjemsland, Water and Sewer Utilities ManagerAl Chrisman, Water Reclamation Facility SupervisorJim McBride, Water Reclamation Facility OperatorTyler White, Water Reclamation Facility OperatorNathan Gaul, Water Reclamation Facility OperatorHank Arnold, Water Reclamation Facility Operator

Presentation Outline

Introduction/Project LocationExisting WRFProject HistoryProject ObjectivesExpansion Plan OptionsDescription of WRF Expansion ImprovementsExpanded WRF PerformanceThoughts and Observations

SecondaryClarifiers

Anoxic Zones

(zero D.O.)Aeration BasinSelector

Zone

Screened

Influent AIR

Return Activated Sludge (RAS)

Secondary

Effluent

Recycle

Water Reclamation Facility Location

City of

Sequim

City of

Sequim

City of Sequim

WRF

Sequim Water Reclamation Facility

Sequim Water Reclamation Facility

Original 0.8 MGD Water Reclamation Facility Site Plan

Original Water Reclamation Facility Schematic

EXISTINGOXIDATION DITCH

EXISTING PEAKFLOW

EQUALIZATION BASIN

SECONDARYCLARIFIERS

(2)

SELECTOR/DIVERSION

BOX ANTHRFILTER

UV EFFLUENTCHANNEL

LIFTSTATION

HEADWORKS/SCREENINGS

REUSELIFT

STATION

VOL = 0.70 MG

VOL = 0.70 MG

50‐FT DIA

Design Flow = 0.8 MGD Max Month Average

Equalized Peak Hour Flow = 1.8 MGD

Original Water Reclamation Facility Site

Original Water Reclamation Facility Site

Original Oxidation Ditch

Secondary Clarifier

Anthracite Filter

Original Ultraviolet Disinfection System

Effluent Channel and Holding Pond

Aerobic Sludge Digester and Class A Biosolids Treatment System

Class A Biosolids Treatment Equipment

Reuse Sites and Pipeline

Interpretive Center Entrance

Surface Irrigation

Storage Pond

Channel to Bell Creek

Water Reclamation Facility Expansion Project History

April 2003

Wastewater Comprehensive Plan issued. Annual growth rate of 1.4% used.

2004‐2005

City attempted to line up regional partners as WRF load approached design capacity.

May 2005 NPDES Permit with new effluent nitrogen limits

issued by Department of Ecology.

2006

Lack of commitment among some of the regional partners and increasing growth in the

City leads to decision to upgrade 0.8 mgd WRF without regional partners.

Water Reclamation Facility Expansion Project History (continued)

January 2006 City indicated that new City Comprehensive

Plan will use annual growth rate of 6.5%.

May 2006

WRF Expansion Study started. Annual growth rate of 6.5% for 2006‐2011 and 5% for

2012‐2025 used.

December 2006

WRF Expansion Study issued, including conceptual plan for expansion of WRF and

reuse sites.

March 2007 WRF expansion design started.

Water Reclamation Facility Expansion Project History (continued)

April 2008

Final plans and specifications for Phase 1 WRF expansion project are advertised for bid.

May 2008

Bids for WRF expansion project opened.

July‐October 2008

Construction of WRF expansion project started.

March‐June 2010

Construction of WRF expansion project completed/startup.

Water Reclamation Facility Expansion Project Objectives

Meet regulatory requirements for nitrogen removal.

Provide capacity for existing population and growth.

Accommodate WRF layout for long‐term growth.

Meet Water Reclamation and Reuse Standards/satisfy Departments of Ecology and Health design requirements for Class A WRF.

Water Reclamation Facility Expansion Project Objectives (Continued)

Remain on the existing WRF site.

Provide cost‐effective design (limited budget).

Allow construction phasing for future expansion.

Incorporate flow equalization.

Expand existing Class A biosolids treatment system.

Projected WRF Influent Maximum Month Flows (2006 WRF Expansion Study)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

2000 2005 2010 2015 2020 2025 2030

Flow

(mgd)

Year

NPDES Permit Criteria for Maximum Month

Projected Sequim WRF Maximum Month Flow @ 1.4% Growth Rate, 2% Annexation Rate (Used in 2003 Sewer Comp Plan)

Projected Sequim WRF Maximum Month Flows @ 6.5% Growth Rate for 5 years, 5% Growth Rate for Remainder, Complete Annexation of UGA within 20 years

WRF at Capacity Phase 1A Const.

Phase 1B Construction

Phase 2 Construction

Flows and Loadings (2006 WRF Expansion Study)

0.00

0.50

1.00

1.50

2.00

2.50

3.00

2005 2010 2015 2020 2025

Flow

(mgd)

Year

Maximum Month Flow

Peak Hour (Equalized) Flow

Two Secondary Clarifiers Exceed CapacityPhase 1A Exceeds Capacity

Filters ExceedCapacity

Existing Oxidation Ditch Exceeds Capacity(NPDES Permitted Design Flow 0.8 mgd)

Existing UV System Exceeds Capacity per NWRI Standards

Converted Activated Sludge Basin Exceeds Capacity Phase 1B Exceeds Capacity

Phase 1A Construction

Phase 1B Construction

Phase 2 Construction

Design Year

Construction Schedule and Design Flows

Existing Phase 1A Phase 1B Phase 2

Construction Start Year 1995 2008 2012* 2019‐2020

Year Capacity Will Be Reached 2008 2013 2020 2025

Design Average Flow Capacity

(mgd)

0.8 1.10 1.67 2.23

Eq. Peak Hr Flow Capacity (mgd) 1.80 1.80 2.46** 3.16

Notes: *Phases 1A and 1B started construction in 2008.

**4.65 mgd unequalized peak hour flow

Plant Design Flows and Loadings

Existing

Permit

Estimated

Actual Expansion

Factor

Increase

Annual Average Flow NS 1.50 mgd

Maximum Month Flow 0.80 mgd 0.68 mgd 1.67 mgd 2.5

Peak Hour Equalized Flow 1.80 mgd 2.46 mgd

Maximum Month BOD5 1,725 lb/d 1,450 lb/d 4,036 lb/d 2.8

Maximum Month TSS 1,450 lb/d 3,855 lb/d

Maximum Month TKN NS 776 lb/d

NS – Not Specified

Reclaimed Water Limitations

Parameter Average Monthly Average Weekly

BOD5 30 mg/L 45 mg/L

TSS 30 mg/L 45 mg/L

Turbidity 2 NTU 5 NTU

Total Coliform Bacteria 2.2 MPN/100 ml (7‐day median) 23 MPN/100 ml (max.)

Ammonia (as N) 3.3 mg/L 5.7 mg/L (daily max.)

Total Nitrogen (as N) 10 mg/L NA

pH ≥6 (daily min.) ≤9 (daily max.)

Dissolved Oxygen >0 mg/L

Nitrogen Removal in Original Oxidation Ditch

Nitrogen Removal in Oxidation Ditch Maintained Aerobic/Anoxic Zones

To SecondaryClarifier

Influent

RAS

Aerator ON

AEROBIC ZONE

ANOXIC ZONE

Aerator OFF

WRF Expansion Options Evaluated

NEW FLOWEQUALIZATION BASIN

CONVENTIONAL ACTIVATEDSLUDGE MLE BASIN #1

(CONVERTED FROM EXISTINGOXIDATION DITCH)

CONVENTIONAL ACTIVATEDSLUDGE MLE BASIN #2

(CONVERTED FROM EXISTINGEQUALIZATION BASIN)

SECONDARYCLARIFIERS

(2)

SECONDARYCLARIFIERS

(1)

EXPANDEDSELECTOR/DIVERSION

BOX

NEW SPLITTER

BOX

ANTHRAFILTER

NEWFILTER

UV1

UV2

EXISTING

NEW

EXISTING

NEW

VOL = 0.75 MG

EXPANDED LIFT

STATION

WRF Expansion Alternative No. 1 Conventional Activated Sludge in Existing

Oxidation Ditch Tanks

VOL = 0.70 MG

VOL = 0.70 MG

NEW MEMBRANEBIOREACTOR BASIN

EXISTINGOXIDATION DITCH

EXISTING FLOWEQUALIZATION

BASIN

SECONDARYCLARIFIERS

(2)


BOX ANTHRAFILTER

UV1

UV2

EXISTINGLIFT

STATION

NEWLIFT

STATION

NEW

EXISTING

VOL = 0.5 MG

VOL = 0.70 MG

VOL = 0.70 MG

WRF Expansion Alternative No. 2 New Membrane Bioreactor Tank

EQUALIZATION BASIN(CONVERTED FROM EXISTING

OXIDATION DITCH)

MEMBRANE BIOREACTORBASIN (CONVERTED FROM

EXISTING EQUALIZATIONBASIN)


BOXUV1

UV2NEW

LIFTSTATION

VOL = 0.70 MG

VOL = 0.70 MG

NEW

WRF Expansion Alternative No. 3 Membrane Bioreactor in EQ Basin

EQUALIZATION BASIN(CONVERTED FROM EXISTING

OXIDATION DITCH)

CONVENTIONAL ACTIVATEDSLUDGE MLE BASIN

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -CONVERTED FROM EXISTING

EQUALIZATION BASIN

SECONDARYCLARIFIERS

(2)

SECONDARYCLARIFIERS

(1)

NEW SPLITTER

BOX

ANTHRAFILTER

NEWFILTER

UV1

UV2

EXISTING

NEW

EXISTING

NEWEXPANDED LIFT

STATION

VOL = 0.70 MG

VOL = 1.35 MG

WRF Expansion Alternative No. 4 Conventional Activated Sludge in Enlarged EQ

Basin (Selected Alternative)

Convert Original EQ Basin to MLE Aeration Basin

Original Equalization Basin

Original SWD = 10 Feet

Raising Existing Equalization Basin Walls

10 feet to Construct New Aeration Basin

Existing Equalization Basin Walls Raised 10 feet to Construct New Aeration Basin

Constructing MLE Zone Walls in New Aeration Basin

New Aeration Basin Air Diffusers and Internal Recycle Pump

New Aeration Basin Anoxic Zone Mixers

New Aeration Basin Airflow Control Station

New Aeration Basin with Selector/Anoxic/Aerobic Zones

New Aeration Blowers Installed Outdoors in Acoustic Enclosures

New Aeration Basin Constructed from Existing Equalization Basin

Aeration Basin Design Data

Parameter Value

Qty. of Trains 2

Side Water Depth 20.75 Ft

Total Volume 1.35 Mgal

Design MLSS 4,000 mg/L

Aerobic SRT 8.1 days

Selector Zone Volume (Total) 0.06 Mgal

Anoxic Zone Volume (Total) 0.27 Mgal

Internal Recycle Flow (Total) 5,200 gpm

Design Recycle Ratio 4 : 1

Blowers 3 @ 850 scfm/ea. (75 hp)

Air Diffusers Fine bubble disc

membrane

Convert Original Oxidation Ditch to New In‐Line EQ Basin

Original Oxidation Ditch

Converting Existing Oxidation Ditch to New Equalization Basin

Installing Influent Lift Pumps in New Equalization Basin (Old Oxidation

Ditch)

New Equalization Basin (Old Oxidation Ditch)

Original High‐Flow Diversion/Selector Box Converted to Clarifier Splitter Box

Original High‐Flow Diversion/Aerated Selector Box

Clarifier Splitter Box

Original Shallow Clarifier Walls Raised to Increase Side Water Depth

Original Shallow, Peripheral‐feed Secondary Clarifier

Increase Depth by Modifying Existing Secondary Clarifier Wall & Peripheral Launder

New Center‐feed/Spiral Scraper Equipment in Existing Secondary Clarifier

New Equalization Basin and Modified Secondary Clarifier

New 50‐foot Dia. Secondary Clarifier Constructed

New 50‐foot Diameter Secondary Clarifier (Third Clarifier)

Supplemental Filtration Capacity Installed

Supplemental Package Effluent Filter and FRP Flocculation Tanks

Higher Capacity Filter Lift Pumps Installed in Existing Sump

Fecal Coliform Reduction Testing Results in Fabric Filter Regulatory Acceptance

Original Low‐output UV Disinfection System

New High‐output UV Disinfection System in Existing Channels

Existing Effluent Channel and Holding Pond Provide Adequate Detention

Time

Second Lime/Sludge Mix Tank (Old Secondary Clarifier)

Monthly Average Influent Flow

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Sep‐08 Dec‐08 Mar‐09 Jul‐09 Oct‐09 Jan‐10 May‐10 Aug‐10 Nov‐10

Influe

nt Flow

Date

Flow (mgd)

Influent Flow Permit Limit ‐ 1.67 mgd

New Aeration Basin Online

Monthly Average Influent BOD5

and TSS Flows

0

500

1000

1500

2000

2500

3000

3500

4000

4500


Influe

nt BOD5an

d TSS

Date

BOD (lb/d)

TSS (lb/d)

BOD5 Design Load ‐ 4,038 lb/d

TSS Design Load ‐ 3,865


Monthly Average Effluent BOD5

and TSS Concentrations

0

5

10

15

20

25

30

35


Efflue

nt BOD5an

d TSS Co

ncen

tration

Date

BOD (mg/L)

TSS (mg/L)

BOD5& TSS Effluent PermitLimit ‐ 30 mg/L


Monthly Average Effluent Ammonia and Nitrogen Concentrations

0

5

10

15

20

25

30


Ammon

ia and

Total Nitrogen Co

ncen

tration

Date

Total N (mg/L)

NH3 (mg/L)

Total Nitrogen Permit Limit ‐ 10 mg/L


Ammonia Effluent Permit Limit ‐ 3.3 mg/L

Daily 30‐minute MLSS Settleability

0

200

400

600

800

1000

1200


Settled Solid

s

Date

1/2‐hour Settleability (ml)


Daily Average SVI

0

50

100

150

200

250

300

350

400

450


SVI

Date

SVI (ml/g)

New Aeration Basin

Project Construction Cost Summary

Construction* $9,223,532

Cost per Gallon per Day $5.50

Cost per ERU $892

Cost per Pound of BOD5 $2,285* Includes change orders and sales tax.ERUs = 10,343

Thoughts and Observations

Existing tanks can be converted to new treatment process uses to conserve site areaCapacity of existing Aeration Basins can be increased by raising side water depth (though pumping may be required)Oxidation ditch tanks can be converted to plug‐flow aeration basinsInline Equalization Basins can decrease sizes of process units based on peak flowInline Equalization Basins can produce relatively constant loading on downstream processesInline Equalization Basins can be kept free of odor, floatables, and settled solids

Thoughts and Observations (continued)

Inline Equalization Basins can serve as a wet well for plant lift stationClarifiers can have walls raised to increase side water depth and capacityPackage filters can supplement existing filtration capacityHigh‐output UV disinfection systems can replace low‐output units in same channel to increase capacityBlowers in weatherproof, acoustic enclosures reduce housing area requirementsProcess studies can result in regulatory approval of capacity increases without large capital improvementsUse of existing structures for plant upgrades requires consideration of effects on construction schedule, order of work, and means and methods

Questions?

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)

Constant Pump Output =

320 gpm

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)

320 gpm Pump RateFlow Entering PlantPump Flow Rate

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


Overall gain in volume in basin(increase in WSEL)

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


Equalization basin will continue to gain level if pumps remain at

320 gpm

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


Pump speed increase

35.00 ft will trigger a pump adjustmentbased on the rate of change of elevation

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


If lift station pump flow remains at current

increased rate

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


If lift station pump flow remainsat current increased rate

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


The basin level will decrease and

possibly empty

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


Pump speed isadjusted again

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


Pump speed increased

Pump speed is decreased

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


Pump stops

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

0 3 6 9 12 15 18 21 24Time (Hours)

Cum

ulat

ive

Was

tew

ater

Vol

ume

(MG

)


Water level returns tooriginal elevation

Documents

John Jay L. Swift, P.E