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
Mar
-08
Apr
-08
May
-08
Jun-
08
Jul-0
8
Aug
-08
Sep
-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09
Feb-
09
Mar
-09
Apr
-09
May
-09
Jun-
09
Jul-0
9
Aug
-09
Sep
-09
Oct
-09
Nov
-09
Dec
-09
Jan-
10
Feb-
10
Mar
-10
Apr
-10
May
-10
Jun-
10
Influ
ent T
KN
, mg/
L
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
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
Sep
-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09
Feb-
09
Mar
-09
Apr
-09
May
-09
Jun-
09
Jul-0
9
Aug
-09
Sep
-09
Oct
-09
Nov
-09
Dec
-09
Jan-
10
Feb-
10
Mar
-10
Apr
-10
May
-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
8.0
9.0
Jan-
08
Feb-
08
Mar
-08
Apr
-08
May
-08
Jun-
08
Jul-0
8
Aug
-08
Sep
-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09
Feb-
09
Mar
-09
Apr
-09
May
-09
Jun-
09
Jul-0
9
Aug
-09
Sep
-09
Oct
-09
Nov
-09
Dec
-09
Jan-
10
Feb-
10
Mar
-10
Apr
-10
May
-10
Jun-
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
Oct‐08
Nov
‐08
Dec‐08
Jan‐09
Feb‐09
Mar‐09
Apr‐09
May‐09
Jun‐09
Jul‐0
9
Aug
‐09
Sep‐09
Oct‐09
Nov
‐09
Dec‐09
Jan‐10
Feb‐10
Mar‐10
Apr‐10
May‐10
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
