Urban Stormwater R unoff Contamination Associated with Gutter and Pipe M aterial U se
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Urban Stormwater Runoff Contamination Associated with Gutter and Pipe Material Use Olga Ogburn 1 and Robert Pitt 2 1 Graduate Student; Civil, Construction, and Environmental Engineering Department; The University of Alabama 2 Ph.D., P.E., BCEE, D.WRE Cudworth Professor of Urban Water Systems; The University of Alabama http://www.slatetileroofing.com/gallery/images/allred_roof_systems_galler y/copper/copper_gutters.jpg
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Urban Stormwater R unoff Contamination Associated with Gutter and Pipe M aterial U se. Olga Ogburn 1 and Robert Pitt 2 1 Graduate Student; Civil, Construction, and Environmental Engineering Department; The University of Alabama - PowerPoint PPT Presentation
Transcript of Urban Stormwater R unoff Contamination Associated with Gutter and Pipe M aterial U se
Urban Stormwater Runoff Contamination Associated with Gutter and Pipe Material Use
Olga Ogburn1 and Robert Pitt2
1 Graduate Student; Civil, Construction, and Environmental Engineering Department; The University of Alabama
2 Ph.D., P.E., BCEE, D.WRE Cudworth Professor of Urban Water Systems; The University of Alabama
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The Goal
To determine how stormwater quality is affected by the type of gutter and pipe materials, environmental parameters causing degradation of the material, time of contact, and interactions of those factors.
Prior ResearchContribution of rooftop material to runoff water
quality, for example:– Zinc concentrations from uncoated galvanized
metal ranged between 3.5 and 9.8 mg/L (Clark, Long et al., 2008).
– Zinc concentrations from coated galvanized metal were below 0.5 mg/L (Clark, Long et al., 2008).
Effect of pipe material and environmental parameters on drinking water quality, for example:– Iron concentration from PVC pipes reached 0.058
mg/L after 3 days of exposure (Lasheen M.R., Sharaby, C.M., et. al, 2008).
Experimental Design
A series of long-term static leaching testsEight roof and pipe materialsLow and high pH condition
Natural storm water was collected in the city of Tuscaloosa from downspouts and from storm drain inlets.
Materials:
Gutter Materials: vinyl, aluminum, copper, and galvanized steel.
Pipe Materials: concrete, HDPE, PVC, and galvanized steel.
New materialsConcrete pipes - 15 cm longThe rest of pipes - 30 cm long
Experimental Design Containers with pH values of 5 and 8 (using Na2HPO4
* 2H2O and KH2PO4 to create buffers)Sampling times: time zero, 0.5 hr, 1 hr, 27 hr, 1 mo, 2
mo, 3 mo
Measured Parameters:Metals (cadmium, chromium, lead, copper, zinc,
aluminum, and iron)Toxicity (Microtox)pH Nutrients (ammonia nitrogen, total nitrogen, nitrate)
and COD
0
1
10
100
Lead Mass Release per Surface Area of a Pipe/Gutter in Containers with pH 5 and pH 8
P. Steel pH 5G. Steel pH 5P. Steel pH 8G. Steel pH 8
Time, day
Mas
s Re
leas
e pe
r Su
rfac
e A
rea,
m
g/m
2
0.001 0.01 0.1 101
Lead release was observed only for galvanized steel materials during both short and long exposure times.
The loss of lead was higher for containers with pH 8 compared to containers with pH 5.
The highest lead release was noted for galvanized steel pipe at pH 8 and was between 0.628 – 0.710 mg/L (corresponds to 25 - 30 mg/m2).
1
10
100
1,000
Copper Mass Release per Surface Area of a Pipe/Gutter for Containers with pH 5
P. PVC pH 5P. HDPE pH 5P. Steel pH 5G. Vinyl pH 5G. Aluminum pH 5G. Copper pH 5
Time, day
Mas
s Re
leas
e pe
r Sur
face
Are
a,
mg/
m2
0.001 0.01 0.1 101
The highest copper release was observed from copper materials. After 27 hr of exposure copper release was more than 6 mg/L (up to 970 mg/m2).
Copper release was also found in containers with other materials but in much lower concentrations.
1
10
100
1,000
Copper Mass Release per Surface Area of a Pipe/Gutter for Containers with pH 8
P. PVC pH 8P. HDPE pH 8P. Steel pH 8G. Vinyl pH 8G. Aluminum pH 8G. Copper pH 8G. Steel pH 8
Time, dayMas
s Re
leas
e pe
r Sur
face
Are
a, m
g/m
2
0.001 0.01 0.1 101
Lower and slower copper release was observed at higher pH
1
10
100
1000
Zinc Mass Release per Surface Area of a Pipe/Gutter in the Containers with pH 5
P. PVC pH 5P. HDPE pH 5P. Steel pH 5G. Vinyl pH 5G. Aluminum pH 5G. Steel pH 5G. Copper pH 5
Time, dayMas
s p
er S
urf
ace
Are
a, m
g/m
2
0.01 0.1 1001010.001
Zinc losses were the highest for galvanized steel materials Copper materials were the second highest source of Zinc
release-Reached 0.13 mg/L (16 mg/m2) after long time exposure-Higher losses at pH 5
Concrete and Plastic materials were the lowest source of zinc
1
10
100
1000
10000
Zinc Mass Release per Surface Area of a Pipe/Gutter in the Containers with pH 8
P. PVC pH 8P. HDPE pH 8P. Steel pH 8G. Vinyl pH 8G. Aluminum pH 8G. Steel pH 8G. Copper pH 8P. Con pH 8
Time, day
Ma
ss R
elea
se p
er
Su
rfa
ce A
rea
, m
g/m
2
0.001 0.01 0.1 100101
For galvanized steel materials zinc release was greater and faster at higher pH conditions during long exposure After long-time exposure (90 mg/L; 4200 mg/m2 at pH 8)
Concrete and Galvanized Steel Materials
No metals were detected with concrete pipes until 2 months
Lead Copper Zinc0
2
4
6
8
10
12
14
16
Steel Gutters at 27 hrs
pH 5pH 8
Tota
l Met
al C
once
ntra
tion,
mg/
L
Lead Copper Zinc Aluminum Iron0
2
4
6
8
10
12
14
16
Steel Gutters at 3 mo
pH 5pH 8
Tota
l Met
al C
once
ntra
tion,
mg/
L
Lead Copper Zinc Aluminum Iron0.00
0.02
0.04
0.06
0.08
0.10
0.12
Concrete Pipes at 3 mo
pH 5pH 8
Tota
l Met
al C
once
ntra
tion,
mg/
L
Aluminum and Copper Materials
Lead Copper Zinc0.000
0.005
0.010
0.015
0.020
0.025
Aluminum Gutters at 27 hrs
pH 5pH 8
Tota
l Met
al C
once
ntra
tion,
mg/
L
Lead Copper Zinc Aluminum Iron0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Aluminum Gutters at 3 mo
pH 5pH 8
Tota
l Met
al C
once
ntra
tion,
mg/
L
Lead Copper Zinc Aluminum Iron0
1
2
3
4
5
6
Copper Gutters at 3 mo
pH 5pH 8
Tota
l Met
al C
once
ntra
tion,
mg/
L
Lead Copper Zinc0
1
2
3
4
5
6
7
8
Copper Gutters at 27 hrs
pH 5pH 8
Tota
l Met
al C
once
ntra
tion,
mg/
L
Toxicity
At higher pH conditionsConcrete and Vinyl
materials – least toxicCopper and PVC – most
toxic0.01 0.1 1 10 100 1000 10000
-60
-40
-20
0
20
40
60
80
100
Gutters pH 8 @ 5 min
G. Aluminum pH 8G. Aluminum pH 8G. Copper pH 8G. Copper pH 8G. Steel pH 8G. Steel pH 8G. Vinyl pH 8G. Vinyl pH 8
Time, hr
% E
ffect
0.01 0.1 1 10 100 1000 10000
-60
-40
-20
0
20
40
60
80
100
Pipes pH 8 @ 5 min
P. Concrete pH 8 P. Concrete pH 8P. HDPE pH 8P. HDPE pH 8P. PVC pH 8P. PVC pH 8P. Steel pH 8P. Steel pH 8
Time, hr
% E
ffect
0.01 0.1 1 10 100 1000 100001
2
3
4
5
6
7
8
9
10
pH measurements for containers with pH 8
P. PVCP. HDPEP. SteelG. VinylG. AluminumG. SteelG. CopperP. Concrete
Time, hr
pH, u
nitle
ss
ConclusionsThe greatest source of lead, zinc, and iron were
galvanized steel materials, while copper materials were the highest source of copper.
Lead and Zinc release was detected during both short and long exposure .
During short exposure time copper releases were detected only for copper materials at both low and high pH
Copper and aluminum materials had the highest toxicity, while concrete materials were least toxic.
References Clark, Shirley E., Long Brett V., Siu Christina Y.S., Spicher Julia, Steele Kelly
A., 2008 Runoff Quality from Roofing during Early Life. Water Environment Federation.
Lasheen M.R., C.M. Sharaby, N.G. El-Kholy, I. Y. Elsherif, S. T. El-Wakeel, 2008. Factors influencing lead and iron release from some Egyptian drinking water pipes. Journal of Hazardous Materials. 160 (2008) 675-680
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Acknowledgements NSF EPSCoR
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Thank you!
