chrp/managers meeting october 2009 angelo liberti, chief surface water protection office of water...
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CHRP/Managers Meeting October 2009
Angelo Liberti, Chief
Surface Water Protection
Office of Water Resources
401.222.4700 ext 7225
NBC CSO Project
Phase I tunnel - operational Nov 2008
•Post storm monitoring
•Re-assess Rainfall Closure Criteria
Phase II - preliminary design completed
Current Plan for Managing Nutrients From WWTF
• 50% Reduction from RI WWTFs – DEM permits issued – June 2005
• Comparable reductions from MA WWTFs
Revised WWTF Nitrogen Limits• 5 mg/l
– UBWPAD – Woonsocket
• (3 mg/l)
– NBC-Fields Pt.– NBC Bucklin Pt.– East Greenwich
– No. Attleborough
– Attleboro
– Grafton
– Uxbridge
– Northbridge
– (max extent)
• Limits May – October, require operation of treatment to remove N to max
extent possible November-April
– East Providence
– Cranston
– West Warwick
– Warwick
– Smithfield (10 mg/l)
– Burrillville (max extent)
- Warren – anticipated to address impacts to the Palmer River
•8 mg/l
Current Status of Load Reduction Efforts
• 8 - WWTFs have complete upgrades • (2 require additional modifications)
• 1 - Under construction• NBC Fields Point (completion by 12/31/2013)
• 1 – Planning Underway• Woonsocket (Plan was due 8/09, construction by 3/2014)
• 2 - Design Underway• NBC Bucklin Point• East Providence (due 6/01/10, construction by 9/2012
Approximately 30% reduction in RI WWTF load achieved in 2005. Next significant reduction May 2014
Status of Compliance with Revised Permit limits for NMA WWTFs
North Attleborough 8 mg/l EPA issued 2/08; appeals settled (complete construction late 2012)
Attleboro 8 mg/l EPA issued 6/08; Permit upheld on appeal. EAB decision issued 9/15/09.
Upper Blackstone
(UBWPAD)5 mg/l EPA issued 8/08; appeals filed.
Oral arguments before EAB 10/29/09
Grafton 8 mg/l No action to date
Uxbridge 8 mg/l No action to date
Northbridge NA EPA issued 9/06; reduce N to max extent
Status of Compliance with Revised Permit limits for NRI WWTFs
Limit Status Ave TN (mg/l) 5/07-8/08
Cranston 8 mg/l Construction comp. –1/2006. Additional modifications to achieve TP = 0.1 mg/l and consistently achieve TN May-Oct complete construction by 3/31/2013
8.2
Warwick 8 mg/l Construction comp. -11/2004 Additional modifications to achieve TP = 0.1 mg/l and consistently achieve TN May-Oct
8.0
West Warwick 8 mg/l Construction comp. -7/2005. Additional modifications to achieve TP = 0.1 mg/l
9.2 (7.5)*
East Greenwich 5 mg/l Construction comp.–3/2006 4.0
East Providence 8 mg/l Final Design due 6/01/10
Construction Deadline 9/2012
12.3
NBC- Bucklin 5 mg/l Initial Construction Complete 2006
FP approval 10/09, NBC requested 1year 5 months for design.
7.5
* Excludes May data (19.5, 13 mg/l)
Status of Compliance with Revised Permit limits for NRI WWTFs (Cont.)
Limit Status Ave TN (mg/l) 5/07-8/08
NBC -Field Pt 5 mg/l Design Approved 09, Complete Construction 12/31/2013
13.7
Woonsocket 5 mg/l Construction Comp. 2002 Agreed to complete construction for 3 mg/l by 3/2014
6.7
Burrillville Max extent
TN Reductions since 2002 10.5 (7.7)*
Smithfield 10 mg/l Construction comp. -6/2006. Additional changes to consistently meet TP April-Oct
8.3
Warren Anticipated that Warren will need to reduce N to address impacts to the Palmer River
17.7
Westerly Construction comp. 10/03 6.3
Nitrogen Reduction Projections•Nitrogen removal at 11 RI WWTFs - reduces their summer season nitrogen loading by 65%, dropping to 48% as WWTF flows reach approved design flows.
Comparison of MERL Experiments to Providence/Seekonk System
Comparison of observed summer loads to the Providence and Seekonk Rivers with MERL tank levels
12
4
8
16
32
0
10
20
30
40
50
60
70
80
90
100
0 5 10 15 20 25 30 35
Tank case ("x")
DIN
da
ily lo
ad
ing
rate
(m
mo
l/m2
/da
y)
Merl N - load (mmol m-2 d-1)
Observed loads
Area North of Fields Point
Seekonk River
Entire Providence- Seekonk River area
Area north of Bullocks Point
Oxygen Minimum 1981-1983
y = 4.56e-0.0361x
R2 = 0.98
0
1
2
3
4
5
0 20 40 60 80 100
Nitrogen Load (mmol/m2/d)
Ox
yg
en
(m
g/l)
32 X
16 X8 X
4 X
2 X
1 X
C
Allowable Loading Condition
WWTF Name
Approved Design Flow
(MGD)
1 CRANSTON 20.2 2 EAST PROVIDENCE 10.4 3 NARRAGANSETT BAY COMM-BUCKLIN 31 4 NARRAGANSETT BAY COMM-FIELDS 65 5 WEST WARWICK 10.5 6 WARWICK 7.7 7 WOONSOCKET 16 8 UBWPAD 56 9 ATTLEBOROUGH 8.6 10 NORTH ATTLEBOROUGH WWTF 4.6
Evaluation of WWTF Load Reductions
Loading Condition Vs. WWTF Load Reductions
Figure 19: Summary of projected DIN loading rates to selected reaches of the Providence and Seekonk Rivers under four scenarios.
Enrichment levels assuming tributary attenuation
4.2
23.2
9.2
5.2
2.6
17.7
7.9
4.1
1.4
10.0
3.9
2.0
0.9
5.9
2.3
1.2
0
5
10
15
20
25
30
35
no WWTFs TN = DMR TN = 5 TN = 3
Flow = 95-96 Flow = 95-96 Flow = Design Flow = Design
En
ric
hm
en
t le
ve
l
Seekonk River
Fields Pt
Bullocks Pt
Entire Area
Loading Condition Vs. Cost
0
5
10
15
20
25
0 50 100 150 200 250 300 350 400
Capital Cost ($M)
Lo
ad
ing
Co
nd
itio
n (
X)
Seekonk Reach
Fields Point Reach
Bullocks Point Reach
Recommended Option BP, FP, UB, W 5, Others 8
BP, FP, 3 , UB, W 5 Others 8
Anticipated RI WWTF Load Reductions
Average Chlorophyll vs N Load
y = 0.62 x + 6.32
R2 = 0.94
0
10
20
30
40
50
60
70
0 10 20 30 40 50 60 70 80 90 100
Nitrogen Load (mmol/m2/d)
Ch
loro
ph
yll a
(u
g/l)
32 X
16 X
8 X
4 X
2 X
1 XC
Allowable Loading Condition