PCTC

Refined Tar-Based Sealants

Presentation to theCommunity Involvement Committee

of theCity Council

Springfield, MissouriFebruary 24, 2010

Pavement Coatings Technology Council

PCTC

Presentation Outline

• Introduction– Anne LeHuray, PhD (PCTC)

• An Insider’s Perspective– Chris Mariani (Bonsal America)

• Refined Tar-Based Sealants & PAHs in Austin, Texas– Robert P. DeMott, PhD, DABT (Environ)

• Summary & Questions

PCTC

Today’s Presentation• Refined tar-based sealants, formulated & applied

according to ASTM specifications, are effective in protecting & extending the usable life of asphalt

• The experience of the most highly exposed population (i.e., occupational exposures) does not suggest human health concerns

• Follow up studies after the ban in Austin, TX show no discernable difference in either the amount or the sources of PAHs in Austin sediments

• Fingerprint data from Austin and other locations show that refined tar-based sealants are not the predominant source of PAHs in sediments

PCTC

Double ratio plot comparing six coal tar sealant products and two asphalt sealant products (Mahler et al. 2005), runoff from unsealed parking lots, roofs, and roads (Selbig 2009), and sediment from eight urban ponds (Van Metre et al. 2009).

Mahler said she's certain that coal-tar sealants are the prime source of PAH in streams and apartments she surveyed."The only thing it can be is coal tar," Mahler said.

-Columbus Dispatch, Feb. 22, 2010

PCTC

Pollution Control?Or Ban Individual Products?• Policy choice:

– Engineering controls to capture and isolate most pollutants that may enter the environment from paved surfaces

OR– Ban individual products one by one looking for the “magic bullet” that

might solve individual problems• In Springfield, it is only a theory that PAHs might be a problem, as

excessive PAH concentrations have not been found in water or sediment

• It has been said that banning refined tar-based sealants would result in as much as 85 to 90% reduction in PAH loads. What we know about PAHs indicates that is as great a misrepresentation in Springfield as it has been in Austin.

• PCTC urges Springfield not to ban the use of refined tar-based sealants in what we believe would be an ineffective attempt to solve a problem that has not even been shown to exist.

PCTC

PCTC Initiatives

• PCTC Runoff Control Certification Program– Program Goal: Significantly reduce and/or eliminate

sediment runoff from parking lot sealer.– Strategy: SEEM: Standardize, Educate, Enroll and

Monitor.

• New & enhanced PCTC web site– Readily accessible information about BMP– Links to ASTM standards & specifications

PCTC

e. a. Mariani Asphalt19th Street Terminal

A production facility for making asphalt road construction products and pavement sealers, both refined tar and asphalt

based.

Established in 1947, family owned for four generations, employing 75 employees.

Mr. John Haynes, senior driver. Hired in 1982.

MSDS; does NOT contain creosote, pitch, coal dust or chimney soot. Not classified a carcinogen by IARC.

MSDS Asphalt Emulsion, carries similar precautionary language.

Low VOC

10300 Pulaski Highway White Marsh, MD 21162 November 3, 2009 To Whom It May Concern: This is to certify that Gem Seal Fed. Spec. pavement sealer contains less than 50 grams per liter VOC, as determined in accordance with California Air Resources Board (CARB) rules for Volatile Organic Compounds (VOC) of Architectural and Industrial Maintenance (AIM) Coatings, revised as of 6/4/08 to become effective 1/1/10. Gem Seal Fed. Spec. pavement sealer meets the criteria defined according to the most restrictive coating category definition [Driveway Sealers] of this regulation, which lists a corresponding VOC limit of 50 grams per liter maximum.

If you have any questions or need further information, please do not hesitate to contact me. Respectfully submitted,

Geoff Crenson Technical Manager Pavement Maintenance Division

Fume Study presented to NIOSH. Most VOCs registered below detectable levels at typical summer

temperatures.

Test strips applied in Winter/Spring of 2007. Polymer modified ABS and refined tar based.

Test strips today, February 2010

Test Strips, February 2010.

An industry with a 75 year occupational history. A company with 60 year, multigenerational history.

• No elevated adverse health trends – Raw material suppliers

– Coating producers

– Applicators

State of the Science Briefing:PAH Sources and Source Management

On behalf of –Pavement Coatings Technology Council

Robert P. DeMott, Ph.D., DABTEnvironmental Toxicologist

rdemott@environcorp.com

24 February 2010

Overview

Polycyclic Aromatic Hydrocarbons (PAHs)- Ubiquitous human impact

- Well recognized, well studied

New science

Management strategies- Single source bans

- Comprehensive runoff treatment

Background -- PAHs Are Everyday Urban Constituents

From all combustion processes- Vehicle exhaust and power generation

Present in construction materials- Asphalt pavement; roofing; pavement sealers

Consumer products- Shampoos; cosmetics; dyes; medicines; plastics; mothballs

Managing exposure differentiates “pollution” from dandruff control

USGS Authors Recognize Sources

“The presence and distribution of PAHs in the environment are largely a product of the incomplete combustion of petroleum, oil, coal, and wood. Anthropogenic sources such as vehicles, heating and power plants, industrial processes, and refuse and open burning are considered to be the principal sources to the environment.”Van Metre, Mahler and Furlong, 2000. Urban Sprawl Leaves its PAH Signature. ES&T 34: 4064.

One of hundreds of studies

Urban Complexities –Environmental Reality

Pavement Runoff PAHs

Asphalt binder from pavement

Patch and repair products

Pavement sealer (n/a for roads)

Deposited auto exhaust

Motor oil

Tire rubber

Urban Environments are Actually “Polluted”

“Concrete Jungle ….”- Dense human use /

combustion sources

- Impervious surfaces amplify stream inputs

PAH and metals levels in ditches / streams receiving roadway runoff- Collect in sediment

Shampoos and Topical Gels

Denorex Shampoo- 12.5% coal tar solution for

dandruff control

- Product contains “percent levels” of PAHs, yet not perceived to pollute …

- Because environmental loading is managed – treated in WWTP

Sources of PAH Contributions Equivalent to Rain Event on Freshly Sealed Residential Driveway (50m2)

2.7 2.3 2.5 2.3 2.3

0.1

1

10

100

1000

10000

100000

1000000

10000000

1 eyedropper dropused motor oil

3 eyedropper dropsDenorex shampoo

Exhaust from 15 milesof road travelled

Coal tar-sealeddriveway

Rooftop (~1800 sfhome)

PAH

Cont

ribut

ion (m

g)

Source: Mahler, Van Metreet al. 2005

Source: Van Metre &Mahler 2003

Eyedropper

Drop

Used

Motor Oil

Auto Exhaust

15 mi.

3 Drops

Denorex

Sealer

Washoff

Driveway

1800 sf

Home

Rooftop

Runoff

Sources of PAH Contributions Equivalent to Rain Event on Freshly Sealed Commercial Lot (1 Acre)

267 225 190 190 171

0.1

1

10

100

1000

10000

100000

1000000

10000000

1 teaspoon used motoroil

1/2 oz. Denorexshampoo

5 seconds of vehicleexhaust in Austin traffic

One-acre coal tar-sealedparking lot

2 large retail buildings(200,000 sf)

PAH

con

trib

utio

n (m

g)

Source: Mahler, Van Metre et al.

2005

Source: Van Metre &Mahler 2003

1 tsp

Used

Motor Oil

½ oz.

Denorex

5 sec. -

Austin

Vehicle exhaust

Sealer

Washoff

1 acre

lot

2 large

Retail

Rooftops

Runoff

Austin Waterbody PAH Levels Not Extraordinary

Sediment measurements typical – sources: Van Metre et al., 2000. ES&T 34:4064; Geismer report. COA unpubl. results.

Barton SpringsTreasured Resource – Agenda Tipping Point

Barton Springs Pool Area

Barton Springs Tributary Diverted

Asphalt Road Material

Parking Lot Breakdown

Drainage Ditch Below Barton Springs Apartments

USGS/CoA 2005 Study

Mahler, Van Metre, et al. 2005.Parking lot sealcoat: An unrecognized source of urban polycyclic aromatic hydrocarbons. ES&T39:5560

Determined PAH amount washed from coal tar pavement sealer

Could NOT detect different PAH input from coal tar sealer vs. asphalt sealer in-use lots

Limits of 2005 USGS Study

No comparison to:- previously measured PAH loading settling from air

- rooftop runoff to drainage features

No specified proportions of overall PAH loading to waterways

No chemical fingerprinting

Austin Team Produces First Data Quality Act Challenge for USGS

Scope of DQA Challenge

45 statements or topics were challenged - Samples excluded from analysis

- Focus on coal tar sealed lots around 2 mos. old and minimizing number of asphalt-sealed lots

- Misstatement of the outcomes of statistical testing

Authors conceded in whole or in part to 33 issues

Agency “determined that a new version (Version 3) of the report will be released over the Internet as soon as possible.”

Getting it Right Takes Time

USGS among most respected gov’t research organizations

USGS authors respected, long track record

“Speed Kills!”

There is rarely “one” study that tells the story.

Aquarium Tests

Selected doses well above known lethal levels – outcome pre-determined by design

Not yet meet scientific standards requiring description of materials used

- Source of test material not disclosed

- Lack of full chemical characterization precludes repeat by others

City of Austin Input to NY/NJ Harbor Report Rejected

NYAS reconsidered and dropped PAH loading estimate recommended by CoA- Photographic sealer wear-off estimation

- Flawed conceptual design

- Flawed statistical analysis (error in calculations)

NY/NJ Harbor Study Prioritizes Transportation Inputs

“Transportation-related activity (i.e., on-road and off-road engine exhaust, tire wear, and motor oil disposal and leakage) is the source category contributing most greatly to total loadings of PAHs.”

Pollution Prevention and Management Strategies for Polycyclic Aromatic Hydrocarbons in the New York/New Jersey Harbor. 2007. New York Academy of Sciences

‘Nuff Said.

Austin BanBefore And After Sediment Monitoring

Location Selection

12 stream systems around Austin- 16 stations

- 5 sampled before/after flushing rain event

2 highway drainage swale stations

2005 event prior to ban

2008 event (28 mos. post-ban)

Stream Characteristics

•Semi-arid, intermittently dry streambed segments

•Pools and depositional areas limited

•Flash-flood type flows common

Scoured Streambeds Key to “Snapshot” Study Design

•Shoal Creek, urban edge •Waller Creek, near downtown

Highest PAH Concentrations Detected in Urban Areas

0

5

10

15

20

25

30

35

40

Suburban fringe Roadway Urban edge Urban center

ΣPA

H C

once

ntra

tion

(mg/

kg)

Arithmetic Mean PAH Levels Detected in Sediments Sampled in 2005 (Pre-Ban) and 2008 (Post-Ban)

0

10

20

30

40

2005 data 2008 data

Mea

n PA

H C

once

ntra

tion

(ppm

)

PAH Fingerprinting Shows Austin Sediments Do Not Match Coal Tar Signature

0.00.5

1.01.5

BaA/C0

0.70.80.91.01.11.21.31.41.51.6

BaP/BeP

2

3

4

5

6

7Bb

F/Bk

F

CT Test PlotCT Park Lot2008 Data2005 Rain2005 Data

Sample Type

Conclusions

No change in PAH concentrations two years following coal tar sealer ban

PAH fingerprinting shows distinct differences between coal tar-sealed parking lot washoff and Austin stream sediments

Current Technical Bottom Line

USGS authors’ own publications contradict sealers being primary contributor to Austin PAH loading

NY Acad. of Sci. panel rejected CoA estimates of PAH loading and methods of analysis

Sediment sampling before and after the ban demonstrates lack of PAH control in Austin

In the Final Analysis

“For UNSEALED [emphasis added] parking lots (asphalt pavement and concrete combined), the mean ΣPAH was … more than twice the probable effect concentration sediment quality guideline.”Mahler, Van Metre, et al., 2005. Parking Lot Sealcoat: An Unrecognized Source of Urban PAHs. ES&T 39:5560

Removing sealer will not correct stream

conditions

?

Enough Gloom, Where’s the Solution?

Urban PAH Runoff Not Intractable

“Population Pollution” perceived to be impossible to address -- Not True!

Inputs ARE difficult to control

Modern stormwater retention and treatment is effective, however, for controlling environmental releases

PAH Levels in Post-Ban Parking Lot Runoff Samples – 2008 Data

0

2

4

6

8

Pond A Pond B Pond C

Detention Pond ID

Sum

of P

AH

s (p

pm)

Single Product Ban vsComprehensive Protection

Atmospheric

Motor Oil Tire Particles

Road Breakdown

Vehicle Exhaust

Pavement Sealers

Wood Burning

Single Product Ban vsComprehensive Protection

Atmospheric

Motor Oil Tire Particles

Road Breakdown

Vehicle Exhaust

Pavement Sealers

Wood Burning

$

$

$

$

$

$

Single Product Ban vsComprehensive Protection

Atmospheric

Motor Oil Tire Particles

Road Breakdown

Vehicle Exhaust

Pavement Sealers

Wood Burning

$

Differentiating Precautionary from Premature

Science related to PAH releases continues to emerge- EPA major update end of 2010

- Washington DC studies find “usual” sources

Implementing ineffective measures- Misdirects available resources

- Reinforces perceived intractability of PAH issue

Considerations for Policy Makers

Ping-pong policy making - Failure is NOT an option

- Credibility lost for the next initiative

Attack the problem, not the individual- When a sealer ban isn’t enough, which department

gets to have enforcement personnel at traffic lights citing SUV drivers with burning cigarettes?

Does Springfield Want to be Here In 3 years?

0

10

20

30

40

2005 data 2008 data

Mea

n PA

H C

once

ntra

tion

(ppm

)

Or Here….