The Evolution Of an Inlet AWS
Stormwater Inlets
Stormwater Inlet Design and Improvements for Efficient Sediment Capture and Removal
Sediment and Total Suspended Solids in Runoff Total Suspended Solids=Particles in the water column larger than 2 microns Total Dissolved solids= Particles less than 2 microns A human hair is about 75-100 microns
Sediments and Solids
“Solids also provide a medium for the accumulation, transport and storage of other pollutants including nutrients and metals. Sediment bound pollutants often have a long history of interaction with the water column through cycles of deposition, re-suspension, and re-deposition.”From the EPA ‘Preliminary Data Summary Of Urban Stormwater BMP’s’
• “Concentrations of heavy metals and nutrients are inversely related to the particle diameter, which means the highest concentrations are found in the smallest grain sizes that are not picked up by street sweepers” Cheryl Yee in “Road Surface Pollution and Street Sweeping” citing the studies listed below.
(German and Svensson 2002; Revitt and Ellis 1980; Pitt 1979; Vaze and Chiew 2002).
Concentration of pollutants
The idea is simple, Capture pollutants before they make it to the stream
VSFVegetated Stormwater Facilities
Treatment Trains:
Big Facility, Big Inlet, Lot’s of Capture
Forebay traps sediment
Big facility = Big Forebay
Traditional VSF inlets
The Retrofit idea • Paver stones For a mini forebay
From the: Low Impact Development in Western Oregon: A Practical Guide for Watershed Health
Keizer inlets-Retrofit pads
Easy maintenance and Positive Sediment accumulation
Simple inlet retrofit for shovel cleaning 16x16 paver and a hand full of gravel for the base
Slight back grade makes pocket for debris
Note pocket for sediment accumulation
Micro Forebay=Easy Clean!
Curb cut Sized for cleaning?
Measure twice cut once
Proving very effective
Filterra inlets
Leaf and Trash Catcher’s
Bump Out’s
Vegetated Check dam Helps with Pollutant Accumulation And eases Cleaning of the large Forebay pad in this facility.
Locating inlets:
You can really have too much of a good thing?
What’s wrong with this design?
Engineers and builders: Make this width at least a flat head shovel Width and it makes the field maintenance crew’s job much easier.
Vegetation blocking the inlet
Sidewalk Spanners
Good way to get across a sidewalk, but difficult to clean
Well done retrofit to make a sump on this facility.
Concrete Cloth Micro Forebay?
Allows for a flexible moldable shape, but not strong enough for a Vactor to clean.
Fancy Inlets:
Deacidification/Copper Precipitation
Oyster shell
Acidic stormwater
CaCO3(s) + 2 HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)
Plant growth Basic necessity of life
Tomato fertilizer
Carbonate/Hydroxide precipitation of Copper.
“It appears possible to use theoretical solubility curves to reduce the solubility of copper by nearly 100% by boosting pH from acidic to weakly alkaline, while still staying within water quality standards for pH (6.5-8.5).”
Enhancing existing BMPs for improved removal of dissolved metals. WS DOT
Solubility relative to pH
Oyster shells in catch basins for metals hotspots Use oyster shell
for the base of a paver retrofit and benefit from enhanced copper removal.
ODOT sanding
Estimated ODOT District Total Abrasive Use (Cu Yds) Fiscal Years 2003-2017
FY03 2,125 3 11,412 1,031 11,418 3,439 2,449 81 10,762 12,723 29,690 12,511 12,997 6,909 15,099 132,648
FY04 9,512 3,476 23,199 6,144 13,032 5,058 6,411 1,366 12,870 22,946 42,742 17,229 24,519 13,686 25,524 227,715
FY05
No Data
District 2A 2B 2C 1 3 4 5 7 8 9 10 11 12 13 14 TOTAL
FY06 3,566 321 16,778 2,130 23,544 2,360 6,264 2,392 17,485 21,459 40,592 27,547 12,708 15,602 29,993 222,742
FY07 12,029 1,623 15,854 4,830 20,913 3,739 8,754 4,450 20,880 17,878 34,290 21,576 20,660 12,629 24,443 224,548
FY08 13,753 680 22,499 4,559 29,211 4,884 10,601 3,201 39,755 14,078 39,934 29,078 22,840 19,947 42,826 297,846
FY09 16,626 2,903 21,308 3,180 30,180 7,046 9,877 3,641 31,323 17,425 46,516 14,222 17,880 20,585 15,268 257,979
FY10 686 110 16,705 352 25,967 3,541 5,298 556 18,825 13,266 30,766 10,636 9,614 38,663 32,955 207,940
FY11 8,491 371 22,107 2,376 34,266 4,699 10,690 2,466 34,097 20,262 43,383 14,472 17,937 12,364 47,487 275,470
FY12 Dsitrict 38 16,664 5,986 18,567 8,430 6,612 1,273 20,416 10,689 22,575 8,663 9,640 6,793 21,665 158,013
FY13 FY14 FY15 FY16 FY17 2A was merged/split between Districts 1 and 2B 194 3,237 59 747 10,450 22,441 22,380 1,861 28,548 43,017 2,876 5,006 -221 1,058 4,819 26,239 15,585 6,515 19,638 26,702 Salem/Kei 428 4,264 65 3,023 18,469 9,424 10,073 -913 12,942 9,902 27 5,359 199 1,042 3,717 26,444 21,172 13,613 18,409 34,077 15,111 18,275 18,059 12,279 22,835 27,381 41,291 21,907 38,627 50,819 13,309 2,747 1,117 13,427 17,316 11,789 9,536 13,223 5,186 29,745 8,567 7,234 13,381 7,059 17,251 35,420 28,210 8,894 13,371 21,054 199,650 194,369 97,759 175,355 310,174
City of Gresham Sanding/Deicing City of Gresham Sanding/Deicing Data FY 06-07 FY 07-08 FY 08-09 FY 09-10 FY 10-11
Street Sweeping total lane miles total debris
6023 3225
7208 1388
5586 2663
5616 2879
Deicing CMA CMA CMA CMA MgCl/CMA amount (gallons) 2061 816 2730 469 total lane miles 45.55 32 145 5.25
Sanding amount (cy) 21 258 42 total lane miles not tracked for any year snowfall (inches) avg snow in portland oregon from 1981 to 2010 = 3 inches salem = 6.2 inches corvallis = 3.1 inches
FY 11-12 FY 12-13 FY 13-14 FY 14-15 FY 15-16 FY 16-17
5656 2697
5277 2583
MgCl 2372 22
10 0
5611 3809 MgCl
4406 251
? 1
6174 2592 MgCl
5800 2702 MgCl
5800 1800
6276 2281
5173 365
7650 603
7650 276
MgCl 6300 478
MgCl 10123 478
0
35
35
75
334
0
5
3.7
3.7
8 wunderground.com/
City of Salem
Deicer and Sanding Rock Data for City of Salem
Fiscal Year
Deicer – Lane miles
Gallons
Sanding Rock – Lane miles
06/07
1579 ln mi
12,632
285 ln mi
190 cu yds.
07/08
3139 ln mi
25,112
1086 ln mi
724 cu yds.
08/09
4136 ln mi
33,088
3512 ln mi
2342 cu yds.
09/10
643 ln mi
5,144
0
0
10/11
2156 ln mi
17,248
243 ln mi
162 cu yds.
11/12
2328 ln mi
18,624
533 ln mi
355 cu yds.
12/13
569 ln mi
4,552
0
0
13/14
2424 ln mi
19,392
3500 ln mi
2333 cu yds.
14/15
855 ln mi
6,840
0
0
15/16
737 ln mi
5,896
348 ln mi
232 cu yds.
16/17
1697 ln mi
13,576
*5268 ln mi
3512 cu yds.
17/18 to date
57 ln mi
456
0
0
*Extra sanding rock was used in 16/17 due to lack of deicer availability
Cubic Yards
Filtration at a catch basin style inlet Trash Guard Triton Top Hat
Hydrokleen
Poured in place back graded pads
Back grading towards the curb inlet allows a pocket to gather sediment
Simple yet functional inlet design
Lot’s of sediment capture and easy to clean
Sampling the roof sediment traps at City Hall.
Testing Inlet sediment and debris • TCLIP analysis: Toxicity Characteristics Leaching Procedure
• The TCLP analysis simulates landfill conditions. Over time, water and other liquids percolate through landfills. The percolating liquid often reacts with the solid waste in the landfill, and may pose public and environmental health risks because of the contaminants it absorbs. The TCLP analysis determines which of the contaminants identified by the United States Environmental Protection Agency (EPA) are present in the leachate and their concentrations.
The Results:
• The trace metals Chromium and Lead were HIGH compared to UIC sediment sampling (2600 times and 1600 times respectively) • Zinc levels in the sediment liquid were 12 times higher than would be permitted in stormwater by DEQ for UIC stormwater injection • Diesel, gasoline and lube oil all were detected in the roof runoff sediments • Benzopyrene and Mercury levels were Non-Detects. Both these are pollutants of concern and regulated by the DEQ
Questions/Comments?
Mark Akimoff Environmental Program Technician City of Keizer Public Works 503-932-7813
Stormwater Inlet Design and Improvements for Efficient Sediment Capture and Removal
Sediment and Total Suspended Solids in Runoff Total Suspended Solids=Particles in the water column larger than 2 microns Total Dissolved solids= Particles less than 2 microns A human hair is about 75-100 microns
Sediments and Solids
“Solids also provide a medium for the accumulation, transport and storage of other pollutants including nutrients and metals. Sediment bound pollutants often have a long history of interaction with the water column through cycles of deposition, re-suspension, and re-deposition.”From the EPA ‘Preliminary Data Summary Of Urban Stormwater BMP’s’
• “Concentrations of heavy metals and nutrients are inversely related to the particle diameter, which means the highest concentrations are found in the smallest grain sizes that are not picked up by street sweepers” Cheryl Yee in “Road Surface Pollution and Street Sweeping” citing the studies listed below.
(German and Svensson 2002; Revitt and Ellis 1980; Pitt 1979; Vaze and Chiew 2002).
Concentration of pollutants
The idea is simple, Capture pollutants before they make it to the stream
VSFVegetated Stormwater Facilities
Treatment Trains:
Big Facility, Big Inlet, Lot’s of Capture
Forebay traps sediment
Big facility = Big Forebay
Traditional VSF inlets
The Retrofit idea • Paver stones For a mini forebay
From the: Low Impact Development in Western Oregon: A Practical Guide for Watershed Health
Keizer inlets-Retrofit pads
Easy maintenance and Positive Sediment accumulation
Simple inlet retrofit for shovel cleaning 16x16 paver and a hand full of gravel for the base
Slight back grade makes pocket for debris
Note pocket for sediment accumulation
Micro Forebay=Easy Clean!
Curb cut Sized for cleaning?
Measure twice cut once
Proving very effective
Filterra inlets
Leaf and Trash Catcher’s
Bump Out’s
Vegetated Check dam Helps with Pollutant Accumulation And eases Cleaning of the large Forebay pad in this facility.
Locating inlets:
You can really have too much of a good thing?
What’s wrong with this design?
Engineers and builders: Make this width at least a flat head shovel Width and it makes the field maintenance crew’s job much easier.
Vegetation blocking the inlet
Sidewalk Spanners
Good way to get across a sidewalk, but difficult to clean
Well done retrofit to make a sump on this facility.
Concrete Cloth Micro Forebay?
Allows for a flexible moldable shape, but not strong enough for a Vactor to clean.
Fancy Inlets:
Deacidification/Copper Precipitation
Oyster shell
Acidic stormwater
CaCO3(s) + 2 HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)
Plant growth Basic necessity of life
Tomato fertilizer
Carbonate/Hydroxide precipitation of Copper.
“It appears possible to use theoretical solubility curves to reduce the solubility of copper by nearly 100% by boosting pH from acidic to weakly alkaline, while still staying within water quality standards for pH (6.5-8.5).”
Enhancing existing BMPs for improved removal of dissolved metals. WS DOT
Solubility relative to pH
Oyster shells in catch basins for metals hotspots Use oyster shell
for the base of a paver retrofit and benefit from enhanced copper removal.
ODOT sanding
Estimated ODOT District Total Abrasive Use (Cu Yds) Fiscal Years 2003-2017
FY03 2,125 3 11,412 1,031 11,418 3,439 2,449 81 10,762 12,723 29,690 12,511 12,997 6,909 15,099 132,648
FY04 9,512 3,476 23,199 6,144 13,032 5,058 6,411 1,366 12,870 22,946 42,742 17,229 24,519 13,686 25,524 227,715
FY05
No Data
District 2A 2B 2C 1 3 4 5 7 8 9 10 11 12 13 14 TOTAL
FY06 3,566 321 16,778 2,130 23,544 2,360 6,264 2,392 17,485 21,459 40,592 27,547 12,708 15,602 29,993 222,742
FY07 12,029 1,623 15,854 4,830 20,913 3,739 8,754 4,450 20,880 17,878 34,290 21,576 20,660 12,629 24,443 224,548
FY08 13,753 680 22,499 4,559 29,211 4,884 10,601 3,201 39,755 14,078 39,934 29,078 22,840 19,947 42,826 297,846
FY09 16,626 2,903 21,308 3,180 30,180 7,046 9,877 3,641 31,323 17,425 46,516 14,222 17,880 20,585 15,268 257,979
FY10 686 110 16,705 352 25,967 3,541 5,298 556 18,825 13,266 30,766 10,636 9,614 38,663 32,955 207,940
FY11 8,491 371 22,107 2,376 34,266 4,699 10,690 2,466 34,097 20,262 43,383 14,472 17,937 12,364 47,487 275,470
FY12 Dsitrict 38 16,664 5,986 18,567 8,430 6,612 1,273 20,416 10,689 22,575 8,663 9,640 6,793 21,665 158,013
FY13 FY14 FY15 FY16 FY17 2A was merged/split between Districts 1 and 2B 194 3,237 59 747 10,450 22,441 22,380 1,861 28,548 43,017 2,876 5,006 -221 1,058 4,819 26,239 15,585 6,515 19,638 26,702 Salem/Kei 428 4,264 65 3,023 18,469 9,424 10,073 -913 12,942 9,902 27 5,359 199 1,042 3,717 26,444 21,172 13,613 18,409 34,077 15,111 18,275 18,059 12,279 22,835 27,381 41,291 21,907 38,627 50,819 13,309 2,747 1,117 13,427 17,316 11,789 9,536 13,223 5,186 29,745 8,567 7,234 13,381 7,059 17,251 35,420 28,210 8,894 13,371 21,054 199,650 194,369 97,759 175,355 310,174
City of Gresham Sanding/Deicing City of Gresham Sanding/Deicing Data FY 06-07 FY 07-08 FY 08-09 FY 09-10 FY 10-11
Street Sweeping total lane miles total debris
6023 3225
7208 1388
5586 2663
5616 2879
Deicing CMA CMA CMA CMA MgCl/CMA amount (gallons) 2061 816 2730 469 total lane miles 45.55 32 145 5.25
Sanding amount (cy) 21 258 42 total lane miles not tracked for any year snowfall (inches) avg snow in portland oregon from 1981 to 2010 = 3 inches salem = 6.2 inches corvallis = 3.1 inches
FY 11-12 FY 12-13 FY 13-14 FY 14-15 FY 15-16 FY 16-17
5656 2697
5277 2583
MgCl 2372 22
10 0
5611 3809 MgCl
4406 251
? 1
6174 2592 MgCl
5800 2702 MgCl
5800 1800
6276 2281
5173 365
7650 603
7650 276
MgCl 6300 478
MgCl 10123 478
0
35
35
75
334
0
5
3.7
3.7
8 wunderground.com/
City of Salem
Deicer and Sanding Rock Data for City of Salem
Fiscal Year
Deicer – Lane miles
Gallons
Sanding Rock – Lane miles
06/07
1579 ln mi
12,632
285 ln mi
190 cu yds.
07/08
3139 ln mi
25,112
1086 ln mi
724 cu yds.
08/09
4136 ln mi
33,088
3512 ln mi
2342 cu yds.
09/10
643 ln mi
5,144
0
0
10/11
2156 ln mi
17,248
243 ln mi
162 cu yds.
11/12
2328 ln mi
18,624
533 ln mi
355 cu yds.
12/13
569 ln mi
4,552
0
0
13/14
2424 ln mi
19,392
3500 ln mi
2333 cu yds.
14/15
855 ln mi
6,840
0
0
15/16
737 ln mi
5,896
348 ln mi
232 cu yds.
16/17
1697 ln mi
13,576
*5268 ln mi
3512 cu yds.
17/18 to date
57 ln mi
456
0
0
*Extra sanding rock was used in 16/17 due to lack of deicer availability
Cubic Yards
Filtration at a catch basin style inlet Trash Guard Triton Top Hat
Hydrokleen
Poured in place back graded pads
Back grading towards the curb inlet allows a pocket to gather sediment
Simple yet functional inlet design
Lot’s of sediment capture and easy to clean
Sampling the roof sediment traps at City Hall.
Testing Inlet sediment and debris • TCLIP analysis: Toxicity Characteristics Leaching Procedure
• The TCLP analysis simulates landfill conditions. Over time, water and other liquids percolate through landfills. The percolating liquid often reacts with the solid waste in the landfill, and may pose public and environmental health risks because of the contaminants it absorbs. The TCLP analysis determines which of the contaminants identified by the United States Environmental Protection Agency (EPA) are present in the leachate and their concentrations.
The Results:
• The trace metals Chromium and Lead were HIGH compared to UIC sediment sampling (2600 times and 1600 times respectively) • Zinc levels in the sediment liquid were 12 times higher than would be permitted in stormwater by DEQ for UIC stormwater injection • Diesel, gasoline and lube oil all were detected in the roof runoff sediments • Benzopyrene and Mercury levels were Non-Detects. Both these are pollutants of concern and regulated by the DEQ
Questions/Comments?
Mark Akimoff Environmental Program Technician City of Keizer Public Works 503-932-7813
