Porous Pavement in Cold ClimatesPorous Pavement in Cold Climates Part: Performance and CostPart: Performance and Cost

Onondaga Environmental InstituteOnondaga Environmental Institute

17 March 201117 March 2011

Thomas Ballestero, PhD, PE, PH, CGWP, PG, Thomas Ballestero, PhD, PE, PH, CGWP, PG, Robert Roseen, PE, PhD, D.WRE, Robert Roseen, PE, PhD, D.WRE,

James Houle, CPSWQJames Houle, CPSWQ University of New Hampshire Stormwater CenterUniversity of New Hampshire Stormwater Center

Department of Civil Engineering, University of New HampshireDepartment of Civil Engineering, University of New Hampshire

OverviewOverview

1.1. Hydrology of Permeable PavementsHydrology of Permeable Pavements2.2. Water Quality PerformanceWater Quality Performance3.3. Hydraulic PerformanceHydraulic Performance4.4. Cold Climate FunctionalityCold Climate Functionality5.5. Normal MaintenanceNormal Maintenance6.6. Winter MaintenanceWinter Maintenance

22

State of the PracticeState of the Practice

Water quality performance is strong to Water quality performance is strong to excellent depending on designexcellent depending on designHydraulic performance is excellentHydraulic performance is excellentCold climate performance is strongCold climate performance is strongWinter maintenance has tremendous Winter maintenance has tremendous

potential for salt reductionpotential for salt reduction

33

Concerns On PerformanceConcerns On Performance

Little removal of nitrogenLittle removal of nitrogenNo removal of many common ionic formsNo removal of many common ionic formsHowever, a large number of installations However, a large number of installations

STILL continue to be subSTILL continue to be sub--standardstandard

44

Porous Pavement Design OverviewPorous Pavement Design Overview

Porous pavements for new and Porous pavements for new and redevelopment are a watershedredevelopment are a watershed-- based strategy that can both based strategy that can both mitigate impacts for new mitigate impacts for new development and reverse impacts development and reverse impacts in areas with redevelopment. in areas with redevelopment.

Porous pavement (PP) systems Porous pavement (PP) systems combine stormwater infiltration, combine stormwater infiltration, storage, and structural pavement storage, and structural pavement in a single system. in a single system.

PP are a layer cake system, with PP are a layer cake system, with each layer possessing structural each layer possessing structural or water quality purposes.or water quality purposes.

55

66

Porous Asphalt Path, Grey Towers National Historic Site, PA(Source: CH2M HILL)

Porous Asphalt Commercial Parking Lot, Greenland Meadows, Greenland, NH(Source: UNHSC)

Porous Asphalt Section of State Highway, South Portland, ME (Source: ME DOT)

Porous Asphalt Basketball Court, Upper Darby, PA (Source: CH2M HILL)

Porous Asphalt Residential Lane, Pelham, NH(Source: UNHSC)

Parking Lot with Standard Aisle and Porous Asphalt Stalls, Morris Arboretum, Philadelphia, PA (Source: CH2M HILL)

Typical Porous Pavement System Typical Porous Pavement System SectionsSections

77

Typical Section for Storage and Infiltration

Typical Porous Pavement Typical Porous Pavement System SectionsSystem Sections

88

Choker Course: 4”-8” (10 – 20 cm) minimum

Pervious pavement: 4-6” (10 - 15 cm) of porous asphalt

Filter Course: 8” - 12” (20 - 30 cm) minimum thickness of subbase (aka. bank run gravel or modified 304.1)

Native materials

Filter Blanket: intermediate setting bed: 3” (8 cm) thickness of 3/8” (1 cm) pea gravel

Reservoir Course: 4” (10 cm) minimum thickness of 3/4” (2 cm) crushed stone for frost protection, 4-6” (10-15 cm) diameter perforated subdrains with 2” cover

Optional-Liner for land uses where infiltration is undesirable (e.g., hazardous materials handling, sole-source aquifer protection)

Section with Filter Course for Water Quality

Water Quality Water Quality Performance ResultsPerformance Results

1010

Porous Pavements and Pond Water Porous Pavements and Pond Water QualityQuality

100

90

80

70

60

50

40

30

20

10

0

% R

emov

al E

ffici

ency

TSSTPH-D Zn DIN TP

Porous AsphaltPervious ConcreteRetention Pond

‘

TSS Removal PerformanceTSS Removal Performance

1212

1313

1414

1515

Hydrologic Hydrologic Performance ResultsPerformance Results

1717

Hydrologic Performance of Hydrologic Performance of Porous PavementsPorous Pavements

Pervious Concrete (HSGPervious Concrete (HSG--B)B)Porous Asphalt (HSGPorous Asphalt (HSG--C)C)

0

10

20

30

40

50

0 200 400 600 800 1,000Time (min)

Flow

(gpm

)

0

0.03

0.06

0.09

0.12

0.15

5-M

in P

reci

p (in

)

D-Box Flow

Effluent Flow

Precip

0.6 in depth

1818

Flow AttenuationFlow Attenuation

0

10

20

30

40

50

0 500 1,000 1,500 2,000 2,500 3,000Time (min)

Flow

(gpm

)

0

0.03

0.06

0.09

0.12

0.15

5-M

in P

reci

p (in

)

D-Box Flow

Effluent Flow

Precip

2.96 in depth

1919

Lag Time (kLag Time (kLL )) Peak Reduction (kPeak Reduction (kPP ))

55 22 11 0.50.5 0.10.1

Hydraulic PerformanceHydraulic Performance

3/23/20113/23/2011

Curve NumberCurve Number

2020

2121

RESULTSRESULTSRESULTS

2222

Method 1 Q-P

Method 3 Q p

Method 3 Q p

Tbase Tpeak Tcentroid NRCS Folmar88 7 1 1 1 2890 1 1 1 1 510 15 2 2 2 37

Method 2 Lag

MeanMedian

Standar Deviation

2323

Porous Asphalt Surface Infiltration RatesPorous Asphalt Surface Infiltration Rates

Low maintenance sensitivity due to excess infiltration capacityLow maintenance sensitivity due to excess infiltration capacity

Clogged areas can drain to adjacent unclogged areasClogged areas can drain to adjacent unclogged areas

Even with 99% clogging the IR=10 in/hr > most sands & soils

Worst case scenario, no maintenance Worst case scenario, no maintenance performed for performed for 3 yrs3 yrs

Certain areas have reduced IC (drive lanes) while parking areasCertain areas have reduced IC (drive lanes) while parking areasremain unchangedremain unchanged

New England SitesNew England Sites

2424

Infiltration Capacity by AgeInfiltration Capacity by Age

315

7,0454,013

2,598 2,905

54

2,354

140

4,365

10

100

1,000

10,000

100,000

URI-PA-02

UNH-PA-04

URI-PA-04

Grswld-PC-05

Frpt-PA-06

Sski-PA-06

SlvrLk-PA-06

StoYo-PA-06

UNH-PC-07

IC v

ia S

I tes

t (cm

/hr)

2525

How Do They Really Work?How Do They Really Work? 43 in rainfall event in 3 minutes!43 in rainfall event in 3 minutes!

Cold Climate Cold Climate Performance ResultsPerformance Results

2828

Frost PenetrationFrost Penetration

Can be related to pavement failureCan be related to pavement failure

Measured with a Measured with a ‘‘fieldfield--assembledassembled’’frost gauge frost gauge (Ricard et al., 1976)(Ricard et al., 1976)

Show relationships between Show relationships between pavements and soilspavements and soils

2929

Porous Asphalt Frost Penetration Porous Asphalt Frost Penetration

3030

Seasonal Performance EfficienciesSeasonal Performance Efficiencies

0%10%20%30%40%50%60%70%80%90%

100%

TSS TPH-D DIN Zn TP

Retention Pond

Summer

Winter

Annual

3131

Winter Maintenance & Winter Maintenance & Salt ReductionSalt Reduction

Where should reductions occur?Where should reductions occur?

Sources of Salt Loading From Vehicular Surface Deicing

(Rockingham County, NH) (NHDES 2007)

50%

3%27%

9%

11%

Parking Lots

Private Roads

Municipal Roads

State Roads

Other

3333

PA Study Area OrientationPA Study Area Orientation

3434

Measuring Skid Resistance w/ BPTMeasuring Skid Resistance w/ BPT

ASTM STANDARD E303‐93

3535

Lots oneLots one--hour after plowing, hour after plowing, --4*C (11AM on 2/3/07)4*C (11AM on 2/3/07)

PA/DMA Snow & Ice CoverPA/DMA Snow & Ice Cover

PAPA DMADMA

3636

Conditions after thawing and subsequent refreezing (9AM on 3/18/Conditions after thawing and subsequent refreezing (9AM on 3/18/07)07)

No black ice formation on PANo black ice formation on PA

PA/DMA Snow & Ice CoverPA/DMA Snow & Ice Cover

PAPA DMADMA

3737

PC Snow & Ice CoverPC Snow & Ice Cover

Conditions after thawing and subsequent refreezing (1PM on 2/16/Conditions after thawing and subsequent refreezing (1PM on 2/16/08)08)

No black ice formation on PCNo black ice formation on PC

PCPC Stnd. Asphalt Ref. LotStnd. Asphalt Ref. Lot

3838

Shading contributes to amount of cover on PCShading contributes to amount of cover on PC

PC Snow & Ice CoverPC Snow & Ice Cover

PC in sunPC in sunPC in partial PC in partial

sunsunPC in shadePC in shade

Weighted Skid Resistance (BPN)

0102030405060708090

100

100 50 25 0% Salt Application

Skid

Res

ista

nce

(BPN

)

Dense Mix AsphaltPorous Asphalt

0102030405060708090

100

100 50 25 0

% Ic

e C

ov

er

% Salt Application

% Ice Cover

Dense Mix AsphaltPorous Asphalt

Weighted Skid Resistance (BPN)

0102030405060708090

100

100 50 25 0% Salt Application

Skid

Res

ista

nce

(BPN

)

Dense Mix AsphaltPorous Asphalt

PA after spring rain on snow eventPA after spring rain on snow event

DMA after spring rain on snow eventDMA after spring rain on snow event

Effective Salt ReductionsEffective Salt Reductions

Pavement Pavement TypeType

20062006--20072007 20072007--20082008 Reductions Possible Reductions Possible when compared to when compared to

DMA with DMA with 100% App. Rate100% App. Rate

AntiAnti-- Icing Icing Apps.Apps.

Deicing Deicing Apps. Apps.

AntiAnti-- Icing Icing Apps.Apps.

Deicing Deicing Apps. Apps. App. App.

RateRate

Average Average Mass Mass

Reduction*Reduction*((’’0606--’’08)08)

DMA DMA 1515 1414 2323 2222 100%100% 0%0%PAPA 1515 66 2323 2727 25%25% 75%75%

PC PC -- shadeshade -- -- 2323 3131 100%100% --20%20%

PC PC -- sunsun -- -- 2323 2323 100%100% --2%2%

** Reduction possible with no loss in skid resistance (safety)Reduction possible with no loss in skid resistance (safety)

Winter Maintenance GuidanceWinter Maintenance Guidance

Salt reduction potential will be site specific and vary Salt reduction potential will be site specific and vary depending on shading and climate. depending on shading and climate.

Plow after every storm. Plow after every storm.

Apply antiApply anti--icing treatments prior to storms. Antiicing treatments prior to storms. Anti--icing icing has the potential to provide the benefit of increased has the potential to provide the benefit of increased traffic safety at the lowest cost and with less traffic safety at the lowest cost and with less environmental impact. environmental impact.

Deicing is NOT required for black ice development. Deicing is NOT required for black ice development.

Apply deicing treatments during, and after storms as Apply deicing treatments during, and after storms as necessary to control compact snow and ice not necessary to control compact snow and ice not removed by plowing. Excess may be required.removed by plowing. Excess may be required.

4141

Winter Maintenance GuidanceWinter Maintenance Guidance

Mixed precipitation and compact snow or ice is Mixed precipitation and compact snow or ice is particularly problematic for porous surfaces. This is particularly problematic for porous surfaces. This is prevented by appropriate plowing and corrected by prevented by appropriate plowing and corrected by application of excess deicing chemicals.application of excess deicing chemicals.

In certain instances of compact snow and ice, In certain instances of compact snow and ice, excess salt may be required, however loading is excess salt may be required, however loading is offset by the overall reduced salt during routine offset by the overall reduced salt during routine winter maintenance and salt reduction.winter maintenance and salt reduction.

With good sun exposure some porous asphalt With good sun exposure some porous asphalt installations will require no deicing. installations will require no deicing.

Porous asphalt provides exceptional treatment for Porous asphalt provides exceptional treatment for rain on snow events which commonly result in rain on snow events which commonly result in dangerous refreezingdangerous refreezing

4242

Future Research NeededFuture Research Needed

Additional research is needed to examine Additional research is needed to examine salting loading at high loading rates salting loading at high loading rates common to commercial applicationscommon to commercial applicationsMN Recommended application rates of MN Recommended application rates of

3lbs per 1000 square feet appear to be 3lbs per 1000 square feet appear to be exceptionally low in comparison to exceptionally low in comparison to commercial rates.commercial rates.Salt substitutes: water, viscous brineSalt substitutes: water, viscous brine

4343

4444

Post Construction O&M Post Construction O&M

Curing time needs are site specific but there should be at least 24-48 hrs of curing. Common sense clause may lead to lower threshold for small jobs with lighter loading such as when pavement surface is less than 100 F (one- time measurement). Problems occur when the surface temperature is greater than 120 F.

Cost of Porous MaterialsCost of Porous Materials

4545

4646

Cost InformationCost Information~10-20% more for materials 2009, DMA $75-100/ton, PA $89-125/ton placed

by machine for parking and residential road and driveways

Complicated jobs with handwork are more expensive

DMA $2.25/sf, PA $2.80/sf, not including subbase

Costs offset by lack of stormwater infrastructureCost break even is achieved when designing for

quantity management ~Q10-Q25

MaintenanceMaintenance

4747

PrePre--Tx Extent of Debris/CloggingTx Extent of Debris/Clogging

Infiltration capacity via the PreInfiltration capacity via the Pre--Tx DRI test varied from 0 to 53 Tx DRI test varied from 0 to 53 cm/hr, all effectively clogged when slope is considered.cm/hr, all effectively clogged when slope is considered.

4848

PrePre--Tx Tx Infiltration at Infiltration at

Grid LocationsGrid Locations

01,0002,0003,0004,0005,0006,0007,0008,0009,000

D E J G Q H A I F V S N K M W P L U R O B T CTest Location

IC v

ia S

I Tes

t (cm

/hr)

4949

Treatment Effectiveness for Clogged Treatment Effectiveness for Clogged LocationsLocations

0

50

100

150

200

250

300

PW & Vac Soap, PW, & VacCleaning Treatment

Mea

n IC

(cm

/hr)

Pre-Tx ICPost-Tx IC

5050

Pervious Concrete SpallingPervious Concrete Spalling

5151

5252

5353

5454

5555

5656

5757

5858

Boulder Hills, Pelham, NHBoulder Hills, Pelham, NH

2009 Installation of 9002009 Installation of 900’’ of of first PA private residential first PA private residential road in Northeastroad in Northeast

Site will be nearly Zero Site will be nearly Zero dischargedischarge

LID subdivision 55+ Active LID subdivision 55+ Active Adult CommunityAdult Community

Large sand depositLarge sand deposit

Cost 25% greater per ton Cost 25% greater per ton installedinstalled

3/23/20113/23/2011 5959

But there is moreBut there is more……

Salted twice, then never again (less salt to receiving Salted twice, then never again (less salt to receiving stream)stream)

Better traction than standard DMABetter traction than standard DMA Fire fighting storage from rooftop captureFire fighting storage from rooftop capture No concern about mosquitoes in the pondsNo concern about mosquitoes in the ponds

Very little site runoff (pollutant load to stream very Very little site runoff (pollutant load to stream very

small, no thermal pollution)small, no thermal pollution) Receiving stream geomorphic equilibrium not taxedReceiving stream geomorphic equilibrium not taxed

The project sold 2 units in 2009, and 11 units since The project sold 2 units in 2009, and 11 units since

January 2010January 2010……much easier to sell GREENmuch easier to sell GREEN

6060

Questions?Questions?