Session Agenda
1. Why Clean/Green Streets Could be a Game
Changer… Joe Battiata, CWP
2. Prospects for Clean Streets…Cecilia Lane CSN
3. Rolling On: Green Streets/Blue Streets
a) Jason Papacosma, Arlington
b) Charlotte Katzenmoyer, Lancaster
c) Ashley Traut, Baltimore
4. Discussion: How do we move it forward?
Why Clean/Green Streets Could be a
Game Changer in the Bay
• More miles of streets and
highways than streams in
Bay watershed
• Streets are directly
connected IC and often
pollutant hotspots
• Street and Right of Way
owned and/or controlled
by government
• States and locals maintain
and rehabilitate them over
time
Taking a Comprehensive View of Streets
Which mix of strategies make
the most sense to remove
pollutants from our streets:
•Street Sweeping ?
•Catch Basin Cleanouts ?
•Green Street Retrofits
•Blue Alley Retrofits ?
•Storm Drain Outfall Catchers ?
Clean Streets
What are the prospects for nutrient
reduction by cleaning our street
infrastructure ?
Cecilia Lane, Chesapeake Stormwater
Network [email protected]
The Dirt on Dirt
• Review of research on
nutrient content of
sediment and detritus at
various locations in the
urban landscape:
–
–
–
–
–
Streets
Catch basins
Storm Drains
BMPs
Stream Floodplains
Average Nutrient Concentrations of Sediment Related to Common O & M Activities
Practice
Street
Sweeping
TP
(ppm)
Range
TP
Outfall
Net
Filters
513
1,012
FL
UF, 2011
MD
DiBlasi, 2008
FL
UF, 2011
MD
Law et al, 2008
Leaves
only
MD
MWCOG, 1993
Oil Grit
Sediment
only
1,034
381 – 1,437
2,163*
648 – 5,145
1,729
28 – 2,576
637
781*
56 – 5,831
2,769
980
114 – 1,932
3,480*
115 – 12,539
MD
Law et al, 2008
583
100 – 3,863
2,931*
219 – 11,200
Varies
Schueler, 1994
647
448
2,648
321 - 815
557
266
*TKN Values
Notes
CBP, 2011
6,832
4,178 – 12,422
8,050*
404 - 985
220
AVERAGE
Reference
ChesBay
593
Stream
Bank
Sediments
Location
2,500
585
BMP
Sediments
Range
TN
1,000
552
Catch Basins
TN
(ppm)
3,907*
1,293 – 5,500
1,460
160 - 451
FL
UF, 2011
MD
Law et al, 2012
FL
Rushton, 2006
Leaves
only
FL
Rushton, 2006
Sediment only
MD
Stack, 2012
MD
Stack, 2006
Proposed
355
850
MD
MD SHA
550
1,650
PA
Walters, 2012
Rural/Ag
Rural/Ag
714
464 - 937
2,200
1,400 - 3,400
PA
Land Studies, 2004
890
144 – 8,850
2705
3 – 8,250
MD
Stewart, 2008
619
2914
Key Findings
• Surprising consistency in nutrient content
regardless of where sediments are
sampled in urban landscape.
• Greater variability in nutrient content
within individual studies
• Log-normal distribution: median
preferred to means
• Vegetative detritus is also nutrient rich
• Most of the nutrients are organic and
refractory (e.g, TKN). How much will be
biologically available
Makes sense to STOP the
sediments (& associated
nutrients) from getting in there
in the first place.
Strategies for “Capturing”
Sediments
Catch Basin
Cleanout
Street Sweeping
Outfall Net Filters
BMP Maintenance
Stream Restoration
What Defines a “Dirty Street”?
• 2006 MS4 Survey by CWP found that street sweeping
frequency is related to street land use or street type.
• Ex. Commercial >> Residential
• Aesthetics and Demand primary drivers behind sweeping i.e., streets
located in highly visible areas are swept the most
• What other methods do we have to select the
dirtiest streets?
Not all of our
streets behave the
same when it comes
to traffic, runoff
and pollutant
loading
The Original Baltimore Street Sweeping Study was not able to
detect a water quality difference in swept vs. un-swept
streets due to monitoring design problems, but concluded
that intensive sweeping could produce a modest nutrient
reduction benefit…CWP (2008)
Catchment F
Catchment O
Cleaning is Cost-Effective
• Annual cost to remove equivalent annual TN load is
very cost-effective in comparison to other BMPs
Practice
Type of
practice
Street
sweeping
Non-structural
Equivalent
Annual cost
$1,980
Source & Notes
Berretta et al 2011
• CSN is conducting new sweeping cost survey next
month to get better estimates
• We need your help to get the best data!
Street Sweeping
• Expert Panel completed in March 2011
• Existing CBP-approved credit
Qualifying Conditions:
•
•
Urban street with high average daily traffic
volume located in commercial, industrial,
central business, high intensity residential
Minimum frequency of 26 times a year (every
2 weeks)
–
•
Can be grouped for specific times (i.e., Spring
and Fall)
Reductions based on sweeping technology:
Mechanical << Regenerative/Vacuum
Two Methods
1. Mass Loading Approach* (
)
Mass of street dirt collected is measured in tons
at the point of disposal. Multiplied by factors
to determine nutrient reduction credits.
2. Qualifying Street Lanes Method
Localities report the number of qualifying lane
miles they have swept. Determine the
baseline nutrient load using the Simple
Method. Multiplied by “pick-up factors” to
determine nutrient load reduction.
Better credit with Method 1…??
Street Sweeping Example 1
The Mass Loading Approach
MD Community wants to take credit for their street
sweeping program. They have a regenerative street
sweeper with a hopper capacity of 2 tons. On
average they have collected a wet mass of 1.5 tons
over the course of the year.
Street Sweeping Mass Loading Approach
1. Convert tons of wet mass into lbs and
convert to dry weight:
1.5*2000 = 3000 lbs of street solids (wet)
3000*0.7 = 2100 lbs of street solids (dry)
2. Derive nutrient reductions:
2100*0.0025 = 5.25 lbs of TN
2100 * 0.001 = 2.1 lbs of TP
3. Compute TSS Reduction:
2100*0.3 = 630 lbs of TSS
Qualifying Street Lanes Method
Convert qualifying lane miles into total
impervious cover (acres):
Miles swept  feet swept  multiplied by lane
width (feet)  divide by 43,560 = acres of
street swept
Multiply acres swept by pre-sweeping annual
load (simple method):
TP = 2.0 lbs/impervious acre/year
TN = 15.4 lbs/impervious acre/year
Qualifying Street Lanes Method
Multiple pre-sweep baseline load by pick-up
factors:
Multipliers to Reflect Effect
of Street Sweeping on the Baseline Load
Technology
TP
TN
Mechanical
.04
.04
Regenerative/Vacuum
.06
.05
1
CSN 2011
1
Street Sweeping Example
Qualifying Street Lanes Method
Over the past year, local MD community has swept the
streets 26 times, with a regenerative street
sweeper.
The community swept 25 lane miles which included both
sides of the street.
This is converted to an area: Both sides of the street
were swept, so an average width of 20 feet could be
used.
The lane miles were converted to feet and multiplied
the 20’ width, and then divided by 43,560 to get the
total acres of street swept in the past year = 60.61
acres.
Qualifying Street Lanes Example cont.
Multiplying the impervious acreage swept
(60.61 acres) by the pre-sweeping
annual pollutant load, the community
was able to determine their baseline
load:
Baseline Load
Phosphorus (60.61 ac)(2.0 lbs/ac/yr)
= 121.21 lbs/yr
Nitrogen
= 933.39 lbs/yr
(60.61 ac)(15.4 lbs/ac/yr)
Qualifying Street Lanes Example cont.
The MD Community then multiplied the baseline
load by the Regenerative Technology factors
to get load reductions based on their
program:
Pollutant Removal Loads
TP
121.21 lbs/yr*0.06
= 7.27 lbs/yr
TN
933.39 lbs/yr*0.05
= 46.66 lbs/yr
Early Findings
Most jurisdictions will get more nutrient
reduction credit for Method 1
compared to Method 2
Some communities are reporting all their
sweeping activity, and not just the
sweeping that meets qualifying
conditions
Reporting and verification protocols were
never recommended by expert panel
Implementation difficulties for localities
• Trouble getting to
the curb
– On street parking
• What to do in
inclement weather or
winter months?
Key Street Cleaning Issues
• Sweeper technology continues to evolve and improve
• Need better tools to identify the dirtiest streets
• Need for better local reporting, tracking and
verification protocols (USWG)
• Should credits be provided for streets that are
swept less frequently ?
• Locals are struggling to develop more water quality
based street cleaning programs
Catch Basin Cleanout Programs?
• CWP study found that catch basins were rarely
cleaned out to prevent flooding and/or in response to
residential complaints.
• Has been mentioned at USWG as a potential future
expert panel, although existing credit for quarterly
cleanouts.
What’s Next?
• CSN Street Sweeping
Webcast in August 2012
• Need to reconvene an
expert panel to look at all of
the street cleaning options
(including catch basin
cleanouts and net filters) ?
Questions for Discussion
• What methods could we use to identify
the dirtiest streets?
• Should we look at culvert clean-out
credit?
• Would the sediments we pick up have
really ever reached the Bay ?
• What research or management
improvements do we need to perfect
the practice?
Green Streets and Blue Alleys
– INSERT the PANELISTS PREZ HERE
Clean Streets/Green Streets
Arlington, VA
May 24, 2012
Chesapeake Stormwater Retreat
Arlington Watershed Facts
• 2010 Census: 207,627 people
•
•
•
•
•
•
•
Phase I jurisdiction
26 square miles
7,972 persons/square mile
41% impervious cover
334 miles of storm sewers
28.5 miles of perennial streams
Potomac River watershed
Green streets challenges
•
•
•
•
•
•
•
•
Utilities
Utilities
Parking
Limited space
Inflow energy
Small drainage areas
Plant establishment
Community acceptance
Patrick Henry Drive and 9th Rd N
Green streets opportunities
• Plants will grow
• More than a filter:
–
–
–
–
–
Patrick Henry Drive and 9th Rd N
Stormwater volume
Aesthetics
Habitat
Traffic calming
Urban heat island
Visible reminder of our stormwater impacts
Visible part of the solution
Create a plan – think long term
• Contract with Center for Watershed Protection
for retrofit inventory of all watersheds
• Screening and ranking criteria
• ~1,000 projects identified to date
– 2 built
– Many in design
– CIP funding for long-term implementation
Be opportunistic and create partnerships
• Master Transportation Plan
– Includes policy goal to reduce stormwater runoff
from street network
– Green Streets facilities a key implementation tool to
achieve this goal
• Neighborhood Conservation Program
– Local street/pedestrian improvement projects
– Major opportunity to partner
Budget for long-term maintenance

Contact info:
 Phone:
(703) 228-3613
 Email:
[email protected]
 Web:
www.arlingtonva.us
Residents
Environment
Watershed Management
N Albemarle St
Piloting Blue Alleys in Baltimore
Ashley Traut
Blue Water Baltimore
Nick Lindow, P.E.
Greg Hoffmann, P.E.
Biohabitats
Center for Watershed Protection
Background
• Opportunity knocks
– 450 miles of alleys
– 75% impervious downtown
•
•
•
•
Team approach
Cooperation of the City
Interest from funders
Learning from others
City DOT, DPW, Blue Water Baltimore, Center for Watershed
Protection, and Biohabitats inspect a potential bumpout
location in Butchers Hill
The Magic Bullet?
Area
(sf)
Practice
Area (sf)
WQv (cf)
WQv Treated (%)
BH-A-1
Practice
Type
Permeable
Pavement
41,818
3,600
2,997
42%
BH-B-1
Bumpout
7,030
910
504
262%
BH-B-1
Enhanced Tree Pit
5,227
250
375
97%
BH-B-3
Bumpout
10,019
550
718
111%
BH-B-8
68,825
800
4,932
24%
54,450
3,350
3,902
30%
PP-A-3
Bumpout
Permeable
Pavement
Permeable
Pavement
61,420
3,730
4,402
30%
PP-B-2
Bumpout
11,761
520
843
89%
Site
PP-A-1
Combined, retrofits will treat 260k sq ft (6.0 acres):
• Annual runoff treated = 816k cf
• 6.5 lbs/yr TP and 32.2 lbs/yr TN
Reality Check
• Total project cost (budgeted): $1.2 million
• 4.6:1 ratio, potential to viable sites
• Consider slope, utilities, drainage area, closest inlet,
private property conflicts, available space for BMP…
• Learning curve
• Community push back
Lessons Learned (so far)
1. Avoid tunnel vision
Lessons Learned (so far)
2. The more partners the better…sort of
Lessons Learned (so far)
3. Don’t reinvent the wheel
Lessons Learned (so far)
4. Don’t just inform; engage
Lessons Learned (so far)
5. Prove it
Discussion
What are some practical ideas/actions that
we should take in the Bay in the next few
years to get more pollutant reduction out
of our existing and future street
networks ?