Clients People Performance

Design, Construction and Startup of the

First Enhanced Nutrient Removal Plant in Maryland Funded by the

Chesapeake Bay Restoration Fund

Rip Copithorn, Jeff Sturdevant, Vince Maillard

GHD

Introduction

• Chesapeake Bay 2000 Agreement• Maryland, Virginia, Pennsylvania, DC• Reduce N and P by 20 million and 1 million lbs, resp.• Follows the 1983 agreement that resulted in the BNR

program• Enhanced Nutrient Removal (ENR) Program

• ENR Program requires WWTFs to achieve annual average effluent TN of 3 mg/L and TP of 0.3 mg/L

• New limits achieve only 1/3 of the reduction in Agreement

USGS MD-DE-DC Water Science Center

Background • All WWTFs in the

Chesapeake Bay watershed will be subject to strict effluent nutrient loading limits:• Maryland, Pennsylvania,

and Virginia already have nutrient limits

• Delaware, New York, and West Virginia are developing similar requirements

• Maryland has regulations for all 66 major WWTFs

Funding

• All WWTFs 0.5 mgd or greater (total of 66 plants)• Required to upgrade to BNR levels first• ENR eligible items are 100% fundable• Statewide “flush tax” ($50/yr per household)• Easton, MD was first plant to enter the ENR

program in MD in 2003

Easton, MD

Nitrogen Removal

20 mg/L 10 mg/L 5 mg/L 0 mg/L

Nitrification BNR ENR UNR

Easton Goal (3 mg/L)

Permit = 4.0 mg/L

Approximate Limit of Technology

Previous MD Goal/ Standard

Original Permit had NH3 Removal Only

Phosphorus Removal

10 mg/L 1 mg/L 0.1 mg/L 0.01 mg/L

New Permit(0.3 mg/L)

Approximate Limit of Technology

Original Permit (1.2 mg/L)

Previous MD Standard

Overview of Existing Facility

Overland Flow Terraces

Facultative Lagoons

Cl2 & SO2 Buildings

Laboratory

Chlorine Contact

Tank

Outfall

Maintenance Building

Existing Process Flow Diagram

Primary Lagoon

SecondaryLagoon

OverlandFlow

Terraces (5)

PostAeration

Cl2SO2

Raw Influent Outfall

Recycle Pumps

Existing Facility

• Capacity = 2.35 mgd• Limits

BOD5 (6/1 - 10/31) 20 mg/l(11/1 – 5/31) 30 mg/l

Ammonia (6/1 – 10/31) 5 mg/l

New Facility

• Average = 4.0 mgd• Design (Max Month) = 5.5 mgd• Peak Day = 7.8 mgd (higher flows equalized)• Limits

BOD5 (4/1 - 9/30) 11 mg/l(10/1 – 3/31) 30 mg/l

TSS 30 mg/LAmmonia (4/1 - 9/30) 2.1 mg/l

(10/1 – 3/31) 3.7 mg/lTP 1.2 mg/L

Future Limits and Current Goals

On an average annual basis• TN – 4.0 mg/L (goal 3.0 mg/L)• TP – 0.3 mg/L

Biological Process Selection

Workshop 1•Biolac•Orbal•Bardenpho•Schreiber•Batch SBR•ICEAS SBR•5-Stage BNR

•Site Visits•Capital and O&M Cost Estimates

Workshop 2Qualitative and quantitative analysis of remaining alternatives

•Biolac •Orbal•Bardenpho

Selection of EIMCO 5-Stage Bardenpho System

Overview of New Facility

Preliminary Treatment

5-Stage Bardenpho Reactors

Secondary Clarifiers

Operations Building

Pump & Blower Building

Waste Sludge Holding Tanks

Effluent FiltersSolids

Processing Building

Dried Biosolids

Storage SiloUV Disinfection

Easton WWTF Bioreactors

Process includes two (2) parallel oxidation ditches followed by post- anoxic and re-aeration tanks, clarifiers, and deep bed continuously- backwashing up-flow filters

Easton WWTF Bioreactors

Oxidation ditches configured as 5-stage Bardenpho process with a “racetrack” style central aerobic cell aerated w/ vertical shaft surface aerators

Easton WWTF Bioreactors

Process cut-away showing the Bioreactors at the Easton WWTF

OVIVO Eimco Water Technologies (EWT) Carrousel® System Surface Aerator

Anaerobic andPre-Anoxic ZonesAerated “Racetrack”

Zone

Easton WWTF Bioreactors

SCADA control screen for the Bioreactors at the Easton WWTF

Easton WWTF Bioreactor Volume

1The second post anoxic zone was placed into service from October 2008 to April 2009 and October 2009 to March 2010.

Because influent flow and load are only about 60% of the full design values, the plant operators have only operated one of the two bioreactors since the plant went on line.

Treatment Stage

Units in Service (m3) (MG)

Percent of

Reactor Volume

Anaerobic 1 681 0.18 8%Pre Anoxic 1 681 0.18 8%Oxidation Ditch 1 5,867 1.55 70%Post Anoxic 21 908 0.24 11%Reaeration 1 189 0.05 2%Total Volume 8,328 2.2 100%

Volume in Service

Selection of Bio-Solids Treatment Process

• Existing process required no sludge treatment or disposal

• New process will produce approximately 5,000 lbs dry solids per day under average conditions

• Outline of major decisions• Class A or B Bio-Solids • Treatment method to meet Class A or B• Dewatering Method• Storage and/or disposal of final product

New Solids Process Flow Diagram

AeratedHolding Tanks Dryer Storage

SiloCentrifuge

Distribution or DisposalLandfill Daily CoverLandscapingNurseriesFarmsGeneral Public

DisposalLandfill

Construction

• $26,000,000 construction cost (50% BNR, 25% ENR)• Notice to proceed – 12/04• Liquid Processes Operational

• Oxidation Ditch – 10/06 (one train, limited controls)• Filter – 12/06 (no chemical addition until mid 1/07)

• Solids Processes Operational – 1/07• Substantial Completion – 3/07• Startup of Oxidation Ditch w/o seeding• Only one train available for > 50% flow• Limited controls due to sequencing of work

MLSS and Effluent NH3 vs. Time

0

500

1000

1500

2000

2500

3000

3500

4000

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40Time (Days)

[MLS

S] (m

g/l)

0

5

10

15

20

MLSS NH3 (mg/l)

Efflu

ent[

NH 3

](m

g/l)

Effluent Nitrogen

0

1

2

3

4

5

6

7

8

9

10

11

12/15/06 3/25/07 7/3/07 10/11/07 1/19/08 4/28/08

Nitr

ogen

(mg/

L)

Ammonia Nitrate TN TN Goal Average TN

TN Goal

Average TN 3.18 mg/L w/o Supplemental Carbon Addition

Average TN 2.26 mg/L w/o Supplemental Carbon Addition

Average TN 5.52 mg/L

Plant UpsetStart Up

Easton WWTF Nitrogen Removal Performance

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

Jan-

08

Feb-

08

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-08

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-08

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-08

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08

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8

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09

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9

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10

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10

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-10

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-10

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10

Influ

ent T

KN

, mg/

L

0.0

1.0

2.0

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10.0

Efflu

ent N

itrog

en, m

g/L

Influent TKN Effluent TN Effluent NH3 Effluent NO3

4.0 mg/L EffluentTN Goal

Nitrate Concentrations through Process

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Jan-

08

Feb-

08

Mar

-08

Apr

-08

May

-08

Jun-

08

Jul-0

8

Aug

-08

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-08

Oct

-08

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-08

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-08

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09

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09

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9

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10

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10

Mar

-10

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-10

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-10

Jun-

10

NO

3 C

once

ntra

tion,

N m

g/L

NO3 @ Pre Anox Exit NO3 @ Ox Ditch Exit NO3 @ Post Anox Exit

2ndPost-Anoxic Tank Put in Service

Effluent Phosphorus

0.0

0.3

0.6

0.9

1.2

1.5

1.8

12/15/06 3/25/07 7/3/07 10/11/07 1/19/08 4/28/08

Phos

phor

us (m

g/L)

Ortho P TP TP Goal Average TP

TP Goal

Average TP 0.22 mg/L

Average TP 0.66 mg/L

Start UpPlant Upset

Average TP 0.23 mg/L

Easton WWTF Phosphorus Removal Performance

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

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9.0

Jan-

08

Feb-

08

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-08

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08

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8

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10

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10

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-10

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-10

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10

Influ

ent P

hosp

hpor

us, m

g/L

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Efflu

ent P

hosp

horu

s, m

g/L

Influent TP Effluent TP Effluent OP Effluent TP GOal

0.3 mg/L Effluent TPGoal

OP Concentrations Through Process

0.0

5.0

10.0

15.0

20.0

25.0Jan‐08

Feb‐08

Mar‐08

Apr‐08

May‐08

Jun‐08

Jul‐0

8

Aug

‐08

Sep‐08

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‐08

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9

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‐09

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Jun‐10

Ana

erob

ic &

Rec

ycle

OP

Con

cent

ratio

n, O

P m

g/L

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Ox

Ditc

h &

Pos

t Ano

xic

OP

Con

cent

ratio

n, O

P m

g/L

Anearobic Eff OP in Recycle Stream OP @ Ox Ditch Exit OP @ Post Anox Exit

Ongoing Improvements

Questions ?

rip.copithorn@ghd.com