Special Report: Environmental Resources at Risk in the ... · Valley and Philadelphia metropolitan...

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Special Report: Environmental Resources at Risk in the Babcock Creek Subwatershed from the Atlantic City Expressway Expansion

To: South Jersey Transportation Authority; John Stokes, Pinelands Commission; John Bunnell, Pinelands Commission; Lisa Jackson, NJDEP; Mat Klewin, NJDEP; Dave McPartland, NJDEP; Cari Wild, NJ Natural Lands Trust; Chuck Barscz, National Park Service; Paul Kenney, National Park Service; Joe Maher, Atlantic County; Charlie Pritchard, Hamilton Twp.; Bill Christman, Great Egg Harbor River Council; Jamie Cromartie, Richard Stockton College; Emile DeVito, NJ Conservation Foundation; Jon Wager, Conservation Resources Inc.; Carleton Montgomery, Pinelands Preservation Alliance.

The Great Egg Harbor Watershed Association Fred Akers - Administrator P.O. Box 109 Newtonville, NJ 08346 856-697-6114 [email protected] June 10, 2008

LegendAC Expressway Authorit y

Rte50 Dual Lane

Babcock Creek Subwatershed 801

MankillerSubwatershed

Babcock St reams

BabcockCreek2002UrbanLand

Wild & Scenic Federal Boundary

Roads_2007

Map 1

Urban Land Use in the Babcock Creek Subwatershed

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Dear Interested Parties, The purpose of this report is to identify water quality degradation in the area where the Atlantic City Expressway crosses over NJ State Route 50, and to provide data, comments, and recommendations that could be used to support stronger environmental protection measures that could be incorporated into the engineering and design of the planned expansion of the Atlantic City Expressway through the Mankiller Branch and Babcock Creek Subwatersheds. There are a number of sensitive environmental resources in these areas that are especially vulnerable to stormwater discharge rates and volumes, reduced base flow, and substantial road salt discharges in this area from the roads. These resources include Pinelands surface water quality, hydrology and groundwater quality, aquatic life, Atlantic White Cedar forests and other botanicals, and preserved open space. This water quality degradation is also affecting the National Wild & Scenic Rivers System. In 1992, Congress designated 6.95 channel miles and 13.89 water frontage miles of Babcock Creek into the national Wild & Scenic Rivers system based on “Outstanding Resource Values” that include wildlife habitat and botanic values that are representative of the unique Pine Barrens area. Based on the national Pinelands Protection Act and its related Comprehensive Management Plan for the protection of the Pinelands, and the national Wild & Scenic River Act and its related Comprehensive Management Plan for the protection of the Great Egg Harbor River and its designated tributaries, the Great Egg Harbor Watershed Association (GEHWA) in partnership with the Great Egg Harbor River Council and the National Park Service is concerned about the quality of long term resource protection in the Babcock Creek Subwatershed. Starting in 2003, GEHWA and Richard Stockton College conducted a 3 year watershed monitoring project in the Babcock Creek Subwatershed under a grant from NJDEP’s Division of Watershed Management entitled “Adams Branch Stormwater Remediation Plan Phase One”. (http://www.gehwa.org/Adams%20Branch%20Reports.htm ) Our research showed that Pinelands water quality has been historically degraded in the Babcock Creek subwatershed according to NJDEP’s Integrated List reports to the federal Environmental Protection Agency, and our water quality research work from 2003 to 2006 led us to report the following conclusions on page 60 of the Adams Branch report: In addition to the degradation to the PL waters of Adams Branch and Babcock Creek from the land uses of Adams Branch, the land uses from Jack Pudding Branch, Mankiller Branch, and the upper reaches of Babcock Creek are also causing water quality degradation to the PL waters of those two branches and Babcock Creek. During our characterization and assessment work on Babcock Creek we identified roads as being a significant land use stressors to stream health. The Atlantic City Expressway, which is currently a four lane divided highway that cuts completely across the upper subwatershed and bridges over Mankiller Branch, Babcock Creek, Jack Pudding Branch, NJ Route 50, and bridges under County Rte 614 (Cologne Ave.), and County Rte. 670 (Leipzig Ave.), has an especially large impervious footprint with significant stormwater ditches which discharge large volumes of stormwater into all the streams it traverses. We continue to monitor the water quality downstream from the AC Expressway, with a special focus on conductivity as it relates to road salt discharges. During our earlier work we picked up extraordinarily high conductivity in Mankiller Branch (200 to 600 µS/cm) during summer baseflow conditions, and later in 2006 and then in 2008 we picked up higher spikes after snow events with one at 91.4 mS/cm right at the intersection of the AC Expressway and Route 50. Water quality work done by the Pinelands Commission has identified 104 µS/cm as an upper reference threshold for natural Pinelands water conductivity. Note: Seawater Standards have a salinity of 35 or 42.9 mS/cm at 15º C.

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Regional Setting

LegendLa ureldale

Wild & Scen ic Federal Bound ary

Babcock Creek Su bwatershed 801

WMA 15

pinelands

The Regional Setting for the Atlantic City Expressway Expansion is in the Pinelands, in the Babcock Creek Subwatershed, and near

Laureldale in Hamilton Twp,Atlantic County.

Map 2

LegendBabcoc k Streams

Rte50 Dual Lane

AC Expressway

Babcoc k Creek Subwatershed 801

Wi ld & Scenic Federa l B oundar y

PlannedExpansionof ACE

Map 3

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General Table of Contents of Concerns and Findings

1. Road Salt Pollution (page 4): The intersection of the AC Expressway and Rte 50 is a road salt hot spot where specific conductance readings as high as 91.4 mS/cm have been recorded. The long term road salt discharges have created significant environmental accumulations of high conductivity agents that cause the specific conductance of Mankiller Branch to remain at elevated levels all year round, even in the summer. Question: What is the long term impact of this increased conductivity on surface water quality (aquatic ecosystems) and groundwater quality?

2. Extent of Impervious Cover, Stream Connectivity, and Landscape Changes (page 7):

Large extents of impervious surfaces, compacted soils, levees, bridges, culverts, and ditches immediately adjacent to Babcock Creek, Jack Pudding Branch, and Mankiller Branch have changed the natural hydrology, decreasing baseflow and increasing surface runoff. Question: How will these existing conditions and additional impervious surfaces, disturbed soils and vegetation, and new ditches be designed to mitigate the past and future degradation they can generate?

3. Environmental Resources at Risk (page 14): Stands of Atlantic White Cedar, other outstanding botanic resources, aquatic life, preserved open space, the New Jersey Pinelands, and the Great Egg Harbor Scenic and Recreational River all exist downstream from the AC Expressway and NJ Route 50 stormwater discharges. The stormwater discharges and hydrologic modifications from these roads put these outstanding state and national resources at risk of being degraded. Question: What engineering designs and best management practices will be employed as part of the expansion to assure the long term protection of these downstream resources?

4. Summary and Recommendations (page 16)

5. Appendix A (page 19): References to Road Salt Research and Highway Planning Considerations

6. Appendix B (page 35); THE IMPERVIOUS COVER MODEL

7. CD inside back cover: Contains a digital version of this report, digital map file, and digital references.

1. Road Salt Pollution The intersection of the AC Expressway and Route 50 is a road salt “hot spot” where specific conductance readings as high as 91.40 mS/cm have been recorded. The long term road salt discharges have created significant environmental accumulations of high conductivity agents that cause the specific conductance of Mankiller Branch to remain at elevated levels all year round, even in the summer. Question: What is the long term impact of this increased conductivity on surface water quality (aquatic ecosystems) and groundwater quality?

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Maps 2 & 3 on page 3 illustrate the area and extent of the Babcock Creek subwatershed, Map 4 on page 6 shows the 5 sampling locations downstream from the Atlantic City Expressway with the highest conductivity results labeled, and Table #1 below presents additional data collected from 2003 to 2008 at those sampling locations. Our earlier sampling data where Holly Street crosses Mankiller Branch gave indications of abnormally high conductivity, so we conducted a source search and identified the primary source of highest conductivity in a ditch at the intersection of the AC Expressway and NJ Route 50. We suggest the notion that the Pinelands are too far south to be affected by road salt is false. There has been no research or studies done about the fate and transport of road salt in the Pinelands that we could find, so we have included two references on the subject from research work done further south in Baltimore and the Chesapeake Bay area in Appendix A. While it is difficult to measure or quantify the actual extent of the water quality degradation that has already occurred, we do know that NJDEP has historically reported to EPA under the Clean Water Act that Babcock Creek and its tributaries are impaired for aquatic life, and that these waters do not attain the designated use standard for pH in the Pinelands Waters. We suggest that conductivity sources with salty water are easily traceable similar to dye tracing, that existing science indicates that there are real long term consequences of road salt use on freshwater systems and soils, and that this condition is a real concern in this area. Taking soil samples from affected areas to determine the concentration and depth of road salt migration from the roadways is another procedure that could be conducted to assess the extent of any degrading impacts. The prescriptions for mitigating road salt and other runoff pollution are found in engineering and best management practices (see Appendix A), which can be tailored to sites at the time of new development like the currently proposed expansion of the expressway. Also, new practices like the application of liquid brine from tanks without sand are now being used, which may need to be regulated in some form to measure the extent of their negative impact to the environment.

Table 1

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Legend

Mankill erSampli ngPoints

Rte50 Dual Lane

AC Expressway

Mankill erDitches 3 miles

Roads_2007

Mankill erSubwatershed

BabcockCreekAtl ant icWhiteCedar

Wild & Scenic Federal Boundary

Map 4

P1, NJ Route 50 and Expressway Bridge P2, Detained Runoff at NJ Route 50 and Expressway Bridge

Mankiller Branch Subwatershed

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2. Extent of Impervious Cover, Stream Connectivity, and Landscape Changes Large extents of impervious surfaces, compacted soils, levees, bridges, culverts, and ditches immediately adjacent to Babcock Creek, Jack Pudding Branch, and Mankiller Branch have changed the natural hydrology, decreasing baseflow and increasing surface runoff. Question: How will these existing conditions and additional impervious surfaces, disturbed soils and vegetation, and new ditches be designed to mitigate the past and future degradation they can generate? Atlantic City Expressway History Construction of the 44-mile Atlantic City Expressway was begun in 1962 to connect the Delaware Valley and Philadelphia metropolitan area with Atlantic City and other South Jersey shore communities. Its Atlantic City connection was completed in 1965. When the South Jersey Transportation Authority was established in 1991 by the New Jersey Legislature, it was given the responsibility for the Expressway, Atlantic City International Airport and tour-bus travel in Atlantic County. The Expressway reached its full 47-mile length in 2001, when the Atlantic City Connector was completed. It is supported by tolls collected at two barrier toll plazas and five entrance and exit ramps. No state tax money is used. In 2004 the Expressway recorded nearly 63 million toll-paying vehicles, the most ever. Toll revenue reached $57.2 million. The economic benefits to Atlantic City, the Shore and the communities along the Expressway can be seen in the enormous building boom – both among the casino-hotels and in housing. The Atlantic City Expressway was built before current Wetlands Regulations, before the Pinelands Protection Act, before the Wild & Scenic designation of Babcock Creek, and before Phase II Stormwater Regulations. The Expressway was built to cut across the upper portion of the Babcock Creek subwatershed and crosses the Jack Pudding Branch, Babcock Creek, and the Mankiller Branch. The original bridges and drainage systems are very large and now over 40 years old. Considerable initiatives and improvements have been undertaken by the Expressway Authority to mitigate the volume and rate of stormwater runoff over the years. Currently, existing overgrown ditches and emergent habitat are providing increasing ecological services to slow the rate of discharge and reduce pH levels by increasing the time of travel of stormwater runoff. For the most part, sedimentation from the AC Expressway in this area is currently not a significant issue. We do however, have a serious concern that cleaning out the existing old ditches and adding additional impervious surfaces and new ditches without adequate retention and infiltration will increase the overall rate and degree of downstream degradation, and include new sedimentation. Impervious Surfaces and Compacted Soils The direct relationship between impervious cover and water quality degradation is well known and well documented in numerous scientific studies, and we site “An Integrated Framework to Restore Small Urban Watersheds” prepared by Tom Schueler and the Center for Watershed Protection as one of the best reference for this (see Appendix B). The 1,620 acre Mankiller Subwatershed has 235 acres of Urban Land or 14.5 % of total land use, and the Atlantic City Expressway and the dual lane section of Route 50 account for 55 acres of Urban Land or 3.4%.

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Map 4 below illustrates all six land use types in the Mankiller Branch subwatershed, and Map 5 illustrates the spatial relationship between these major roads and the stream.

Lege nd

Mankil lerSt reams 5 m iles

Mankil ler2002Agri cul ture

Mankil ler2002BarrenLa nd

Mankil ler2002Forest

Mankil ler2002Urban

Mankil ler2002Wate r

Mankil ler2002Wet lands

Mankil lerSubwatershed

Babcock Creek Subwatershe d 801

Wild & Sceni c Fed eral Boundary

LegendMankiller2002Urban ACE 44 acres

Mankiller2002Urban NJ50 11 acresMankillerStreams 2 miles


Map 5

Map 6

Mankiller Branch Subwatershed Land Use 2002

Major Highways Upstream from Mankiller Branch

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Table 2 below catalogs the acreage and percentages of the six land use types for the Mankiller subwatershed. While the subwatershed is 60.2% forested, the 14.5% urban land is significant in this small watershed, and the footprint of the 55 acres of paved road and compacted right of way is directly in the headwaters and uphill from the stream. We believe that given the extent of the pavement and the extent of soil compaction of all these highway lands, that almost this entire highway urban land use delineated by NJDEP is impervious to infiltration. This means that stormwater will run off these impervious surfaces and flow away downstream instead of soaking into the ground, ultimately lowering the seasonal water table and reducing base flow to the headwaters of Mankiller Branch. Table 2: NJDEP Land Cover Data Analysis 1986 to 2002

HUC 14 #: Mankiller Subwatershed (In Acres) (Total Square Miles = 2.53)

Land Use Type 1986 1995 Net Change

2002 Net Change

Total Change

Agriculture 71 4.4%

51 3.1%

-20 68 4.2%

+17 -3

Barren Land 33 2.0%

33 2.0%

0 34 2.1%

+1 +1

Forest 1010 62.4%

1001 61.8%

-9 976 60.2%

-25 -34

Urban Land 201 12.4%

230 14.3%

+29 235 14.5%

+5 +34

Water 4 0.2%

4 0.2%

0 3 0.2%

-1 -1

Wetlands 301 18.6%

301 18.6%

0 304 18.8%

+4 +4

Totals 1,620 1,620 0 1,620 0 0

Impervious 70-4.3% 71-4.4% 1-0.1% 1-0.1% Note: Using ArcView 9.2, NJDEP land use data from 1986, 1995, and 2002 was selected and clipped for this subwatershed. Then each of the six land use types were individually selected and converted into separate attribute tables, and summary data was extracted from these tables and entered into this table for this analysis. And likewise but on a smaller scale, the Atlantic City Expressway and its large right of way have similar impacts to Babcock Creek and Jack Pudding Branch. Maps 7 and 8 on page 10 show this, and Table 3 on page 11 illustrates a growing urban footprint in a historically forested subwatershed with high ecological integrity.

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Lege nd

BabcockCreek2002LandUseTY PE02

AGRICULTURE

BARREN LAND

FOREST

URBAN

WAT ER

WETLANDS

Babcock_St reams

Wi ld & Sceni c Federal Boundary

LegendB abco ckCreek2002Urban ACE 132 acres

B abco ckCreek2002Urban NJ50 11 acres

B abco ck_Stream s

B abco ck Creek Subwatershed 801

Wil d & Scenic F ederal B oundary

Map 7

Babcock Creek Subwatershed Land Use 2002

The AC Expressway transects the subwatershed

Map 8

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Table 3: NJDEP Land Cover Data Analysis 1986 to 2002

HUC 14 #801: Babcock Creek (In Acres) (Total Square Miles = 20.1)

Land Use Type 1986 1995 Net Change

2002 Net Change

Total Change

Agriculture 860 6.7%

829 6.4%

-31 857 6.7%

+28 -3

Barren Land 147 1.1%

88 0.7%

-59 155 1.2%

+67 +8

Forest 6859 53.3

6588 51.1%

-271 6306 48.9%

-282 -553

Urban Land 1453 11.3%

1796 14.0%

+343 1974 15.3%

+178 +521

Water 52 0.4%

73 0.6%

+21 61 0.5%

-12 +9

Wetlands 3509 27.2%

3506 27.2%

-3 3527 27.4%

+21 +18

Totals 12,880 12,880 0 12,880 0 0

Impervious 432 10.7%

698 13.5%

266 2.8%

266 2.8%

Note: Using ArcView 9.2, NJDEP land use data from 1986, 1995, and 2002 was selected and clipped for this subwatershed. Then each of the six land use types were individually selected and converted into separate attribute tables, and summary data was extracted from these tables and entered into this table for this analysis. Hydrologic impacts of levees, bridges, culverts and ditches The roadways built up on compacted soil in this area now act as levees that block and divert natural water flow and stormwater runoff. A series of bridges, culverts, and ditches have been engineered to direct and divert the stormwater runoff and natural surface flows under and around the levees to prevent flooding from stormwater runoff and any natural high groundwater levels. This entire manmade infrastructure has significantly interrupted and modified natural surface water flows. Most of the ditches for the AC Expressway are very wide, and in some cases very deep. In general, we assessed the size of the ditches as being significantly larger than the natural channel morphology of Mankiller and Jack Pudding Branches. The large ditch size offers considerable water storage capacity, and in some cases these large ditches act to detain, retain, and evaporate and infiltrate stormwater, which offers some control of discharge rate and volume. Note: All of the stormwater from NJDOT dual lane Route 50 is collected and discharged into the AC Expressway ditch system.

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But in some cases, the ditches have been dug into the water table upstream from the natural headwater sources (especially of Mankiller Branch), which tends to artificially increase groundwater discharge rates in late winter and early spring, and then causes the artificial lowering of the water table and reduced groundwater baseflow in the summer. This has a significant negative impact on the seasonal hydrology of the natural aquatic ecosystems in this area, and the extent of this accelerated groundwater discharge may be a factor in the low pH measurements in Mankiller Branch as compared to the much higher pH further up the ditches near the pavement at the intersection of Rte. 50 and the Expressway. Today, over three miles of large manmade ditches directly connect with and expedite the drainage of large volumes of stormwater runoff from the AC Expressway and NJ Rte 50 into 2 stream miles of Mankiller Branch, which then discharges into Babcock Creek, which is part of the National Wild & Scenic Rivers System. Map 9 below illustrates the overall connectivity between the 3 mile ditch system that discharges into Mankiller Branch. Maps 10 and 11 on page 13 show in greater detail how the ditch system relates to the existing roads and wetlands. Concrete culverts are used to connect ditches under the roads. Existing overgrown ditches and emergent habitat are providing some ecological services to slow the rate of discharge and help to also reduce pH levels by increasing the time of travel of the stormwater. However, we have serious concerns that cleaning these ditches out and adding additional impervious surfaces and new ditches without adequate retention and infiltration will increase the rate and degree of downstream degradation.

LegendManki lle rDitches 3 miles

Manki lle rStreams 2 mi les

Rte50 Dual Lane

AC Expressway Authori ty

Manki lle r2002Wetlands

Manki lle rSamplingPoints

Roads_2007

Manki lle rSubwatershed

Wi ld & Scenic Federal Boundary

Map 9

Mankiller Subwatershed Wetlands Complex

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LegendM ankil le rDi tches 3 m iles

M ankil le rStreams 2 miles

M ankil le r2002Urban NJ50 11 acres

A C Expressway Author ity

M ankil le r2002Wetlands

M ankil le rSamplingPoints

Roads_2007

LegendMankillerDitches 3 miles

MankillerS tream s 2 miles

Mankiller2002Urban NJ50 11 acres

AC Expressway Authority

Mankiller2002Wet lands

MankillerSamplingPoints


Roads_2007

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3. Environmental Resources at Risk Stands of Atlantic White Cedar, other outstanding botanic resources, aquatic life, preserved open space, the New Jersey Pinelands, and the Great Egg Harbor Scenic and Recreational River all exist downstream from the AC Expressway and NJ Route 50 stormwater discharges. The stormwater discharges and hydrologic modifications from these roads put these outstanding state and national resources at risk of being degraded. Atlantic White Cedar and other outstanding botanic resources Preserving Atlantic White Cedar wetlands from degradation has been one of the fundamental themes of land preservation throughout New Jersey. In May 2008, the Conserve Wildlife Foundation published an article at http://www.conservewildlifenj.org/explorations/may08/atlanticcedar.html that highlights the importance of preserving, and the difficulties of restoring, Atlantic White Cedar forests. We offer the following quote from this source: Called “the cathedrals of the Pine Barrens” by noted Pinelands author and naturalist Howard Boyd, groves of Atlantic white-cedar were once commonplace in the Pinelands and also along the Atlantic and Gulf coasts from southern Maine to Florida. Today, centuries of improper logging, hydrologic changes, flooding from beaver, development and wildfire have reduced the number of stands of white cedar and as a consequence, habitat for imperiled species and breeding birds. According to NJDEP’s 2002 land use mapping, there are 8 acres of Atlantic White Cedar downstream from the AC Expressway in the riparian floodplain corridor of Mankiller Branch, and another 15 acres in the floodplain a mile below the confluence of Mankiller Branch and Babcock Creek. Most of these Atlantic White Cedars are already on preserved land owned by the New Jersey Natural Lands Trust for their Mankiller Preserve, and NJDEP as part of their Makepeace Lake Wildlife Management Area. In addition to the cedar wetlands, approximately 1/3 of the 3,527 acres of over 12 different wetland types in the Babcock Creek subwatershed are within the floodplains of Mankiller Branch and Babcock Creek downstream from the AC Expressway. All of these wetlands are in the Pinelands, some are in the federal Wild and Scenic boundary, and many are located on already preserved open space. Map 15 on page 18 illustrates the location of the Atlantic White Cedar and the extent of the wetlands in the Babcock Creek subwatershed. Aquatic Life According to NJDEP’s Integrated List reports to the US Environmental Protection Agency for compliance to the Clean Water Act, Aquatic Life and pH are two regulatory parameters that historically do not meet the designated uses for the Pinelands. Because the Pinelands is a National Reserve, the Pinelands Waters (PL) are classified as Outstanding National Resource Waters, and have high quality standard for designated uses. One of the highest designated uses for the PL waters is for the “maintenance, migration and propagation of the natural and established biota indigenous to this unique ecological system” as codified in the NJDEP Surface Water Quality Standards at 7:9B-1.12.

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While there are multiple stressors which create cumulative impacts that can degrade water quality, we suggest that given the fact that over 76% of this subwatershed was forest and wetlands in 2002, that the stormwater discharges and hydrologic changes from NJ Rte 50 and the AC Expressway are major contributors to the water quality issues in this subwatershed. Most recently in the 2006 Integrated Report published by NJDEP, the entire subwatershed was on List 5 for Aquatic Life Impairment, and the pH surface water quality criteria of 3.5 to 5.5 codified under N.J.A.C. 7:9B-1.14 was “Non Attained” for the entire subwatershed. Map 12 below illustrates the segments that were measured or estimated to be impaired by NJDEP from their 2004 Integrated Report, along with their biological monitoring stations for aquatic life.

Preserved Open Space Multiple themes for open space preservation have been and continue to be worked on in this subwatershed. From the early days of the Pinelands Commission, almost the entire subwatershed area below the Atlantic City Expressway was identified as the Babcock Swamp Elwood Corridor preservation area based on its ecological values (bright green on Map 13 on page 16). In response to this designation, the Pinelands Commission also mapped much of the area below the Atlantic City Expressway as a priority land acquisition area to protect this important part of the Pinelands (Orange on Map 13).

LegendMankillerDit ches 3 miles

Babcock St reams



BabcockCreekBioPoints

BabcockCreek_ir_2004

Roads_2007




Map 12

Water Quality Impaired Stream Segments

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Today, approximately 2,414 acres, or about 18% of the Babcock Creek subwatershed, has been preserved through land acquisition. Atlantic County is currently working on an additional preservation project of about 700 acres in the Elwood Corridor, and the New Jersey Natural Lands Trust is continuing to seek out willing sellers to add acreage to their Mankiller Preserve holdings. Map 14 on page 17 illustrates the locations and managing agencies of the preserved land in the Babcock Creek subwatershed. 4. Summary and Recommendations From a watershed management perspective, there are unique natural drainage morphologies and unique manmade land uses and land use trends in every “hydrologic unit” codified (HUC) by the US Geological Survey. A meaningful analysis of these unique attributes and to what extent the manmade land uses effect water quality, natural habitat, stormwater management, flooding, and other measures of ecological integrity and engineering performance is best conducted at the smallest scale possible. NJDEP has set the 14 digit HUC as its smallest scale for subwatershed analysis, and as of 2006 began reporting water quality under the Clean Water Act to the USEPA in terms of subwatershed units

LegendPine lan ds Tar ge t Acq usitio n Ar ea s

Bab co ck Swa m p Elwo od Co rr ido r

M an killer Ditch es 3 m ile s

Bab co ck Str ea ms

M an killer 20 02 Urb an NJ5 0 11 a cr es

AC Ex pre ssw ay Au tho rit y

Ro ad s_2 00 7

M an killer Sub wat ers he d

Bab co ck Cr ee k Su bwa te rsh ed 80 1

Wild & Sce nic Fe de ra l Bou nd ar y

Map 13

Babcock Swamp Elwood Corridor Priority Area (green) and Pinelands Target Acquisition Areas (orange)

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called a HUC 14. There are 921 HUC 14’s in New Jersey with 57 of these in the Great Egg Harbor Watershed, which covers 627 square miles. Babcock Creek is HUC 14 #02040302050020.

With 76% wetlands and forest, and only 15% urban land, Babcock Creek is not an “urbanized” subwatershed, so the historical water quality degradations do not match the overall land use patterns. To get at the source issues, we further reduced our subwatershed scale down to more of a “tributary” level, where we studied the land uses of the Adams Branch and Mankiller Branch subwatersheds more extensively. Our studies at this level revealed that the location and performance of certain urban land uses in relation to the headwaters of the tributaries of Babcock Creek are having a significant and detrimental impact on Pinelands water quality downstream from these land uses. While the location of the headwaters of Adams Branch right in the large urbanized center of the Hamilton Mall/Atlantic City Race Track area was typical of the classic degradation to water quality from urbanized areas, the more liner extent and impact of major highway systems on water quality and the environment is not as obvious or well understood. Our work in the Mankiller Branch subwatershed illustrates how significant the impacts of road development in the headwaters of a small tributary can be, and how similar impacts can be spread completely across the upper portion of a larger subwatershed and affect multiple tributaries and waterways on a subwatershed wide scale.

LegendFarmland Preservation-184 acres

Natural Lands Trust -913 acres

Makepeace WMA-423 acres

Hamilton Twp-894 acres

MankillerDitches 3 mil esBabcock Streams


AC Expressway Authority

Roads_2007


Babcock Creek Subwatershed 801Wild & Scenic Federal Boundary

Map 14

Babcock Subwatershed Preserved Lands

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Our goal in bringing these spatial realities and quality issues to the attention of land use planners, engineers, and state and local agencies is to try to achieve more environmentally protective engineering, design, and best management practices, along with more robust performance management and guarantees for developments like these. While we are not against the expansion of the Atlantic City Expressway and other major roads when expansion is the preferred alternative chosen from a full alternatives analysis, we do want to call on the planners, engineers, designers, and regulatory agencies to do the best possible job when changing and adding to urban land uses that have a direct impact on the water quality, habitat, environmental integrity, and preserved open space downstream from these developments. We are also hopeful that our GIS and data collection work here will be useful to help justify the costs required for getting these kinds of developments done on a “state of the art” level, and for keeping future performance and BMP implementation at the highest possible level. There are many who believe that the human priority should be on development, ratables, and money, and that we simply cannot afford to protect the environment. But we believe that for the long term, we cannot afford not to protect the environment, and that a comprehensive understanding and awareness of environmental resources and values in watersheds will help planners, engineers, and agencies to proactively engineer and maintain the best management practices that get the necessary developments installed while protecting the environment at the lowest possible cost. Otherwise, the public costs of pollution and the costs to mitigate and fix preventable pollution and degradation after the fact are far higher. Fred Akers

LegendBabcockCreekAt lant icWhiteCedar

BabcockCreek2002Wet lands

Babcock St reams

MankillerDitches 3 miles




Roads_2007



Map 15

Wetlands and Cedar in Babcock Creek Subwatershed

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Appendix A

References to Road Salt Research and Highway Planning Considerations From icy roads to salty streams Robert B. Jackson*† and Esteban G. Jobba´gy*‡ *Department of Biology, Nicholas School of the Environment and Earth Sciences and Center on Global Change, Duke University, Durham, NC 27708-1000; and ‡Grupo de Estudios Ambientales–Instituto de Matema´ tica Aplicada San Luis, Universidad Nacional de San Luis and Consejo Nacional de Investigaciones Cientı´ficas y Te´ cnicas de Argentina, 5700 San Luis, Argentina “A second aspect is their intensive focus on streams in the greater Baltimore area. In this rapidly urbanizing region, they found a logarithmic relationship between the proportion of pavement in a watershed and the mean annual Cl concentration in streams”. Snow, Road Salt and the Chesapeake Bay By Tom Schueler, Center for Watershed Protection “Despite the fact that much of the Chesapeake Bay watershed is situated below the traditional “snow-belt”, it still accounts for much of the road salt used in the country (About a third of all road salt used in the U.S. is applied to states in the mid-Atlantic region)”. Controlling Nonpoint Source Runoff Pollution from Roads, Highways and Bridges EPA, Office of Water, August 1995 (EPA-841-F-95-008a) Road Salts: In the snowbelt, road salts can be a major pollutant in both urban and rural areas. Snow runoff containing salt can produce high sodium and chloride concentrations in ponds, lakes, and bays. This can cause unnecessary fish kills and changes to water chemistry.

Planning Considerations for Roads, Highways and Bridges EPA, Office of Water, October 1995 (EPA-841-F-95-008b) Snow and Ice Control

• Cover salt storage piles and other deicing materials to reduce contamination of surface waters. • Locate them outside the 100-year floodplain. • Regulate the application of deicing salts to prevent oversalting the pavement. • Use trucks equipped with salt spreading calibration devices. • Use alternative deicing materials, such as sand or salt substitutes, where sensitive ecosystems

should be protected. • Prevent dumping of accumulated snow into surface waters or onto frozen water bodies.

From icy roads to salty streamsRobert B. Jackson*† and Esteban G. Jobbagy*‡

*Department of Biology, Nicholas School of the Environment and Earth Sciences and Center on Global Change, Duke University,Durham, NC 27708-1000; and ‡Grupo de Estudios Ambientales–Instituto de Matematica Aplicada San Luis, Universidad Nacionalde San Luis and Consejo Nacional de Investigaciones Cientıficas y Tecnicas de Argentina, 5700 San Luis, Argentina

For most of human history, saltwas a precious commodity. Peo-ple prized it for flavoring andpreserving food and for use in

religious ceremonies and burials. TheRoman occupation of Britain pepperedthe English language with a legacy ofsalt. We retain those Latin links inwords such as ‘‘salary’’ and ‘‘salami’’ andin place names like Greenwich andSandwich, their suffix denoting a salt-works. Today salt is no longer precious.The U.S. mines �36 million metric tons[1 metric ton � 1 megagram (Mg)] ofrock salt a year (1). Eighteen millionMg is spread on paved surfaces for deic-ing, making winter roads safer for peo-ple and vehicles (2). However, once thesalt dissolves, it washes into streams orsoil and is forgotten. A new article byKaushal et al. (3) in a recent issue ofPNAS suggested that it should not be.

The use of rock salt (NaCl) on U.S.roads has skyrocketed in the last 65years (Fig. 1), and chloride (Cl) concen-trations in waters of the northeast haverisen as a consequence (4–6). The mo-bility of salt in water leads to its poten-tial problems in the environment. Theseproblems include toxicity to plants andfish, groundwater contamination, andhuman health interactions, particularlysalt intake and hypertension (7–9). Inconsequence, researchers have beenmonitoring increased salt concentrationsin streams and groundwater for decades(4–6, 10).

The research by Kaushal et al. (3)documenting increased Cl concentra-tions in streams of the northeastern U.S.is important for several reasons. One isthe long-term nature of their data sets.They analyzed Cl concentrations for20–40 years in seven streams and riversin Maryland, New York, and NewHampshire, showing steady increasesover time. The most dramatic changeswere seen in New Hampshire, where Clconcentrations have increased by morethan an order of magnitude since the1960s, sometimes topping 100 mg�liter�1.Even more importantly, if results areextrapolated into the next century, thedata suggest that many rural streams inthe Northeast will have baseline saltconcentrations �250 mg�liter�1, the gen-erally accepted cutoff for potable waterand a level at which chronic toxicity oc-curs for many freshwater species.

A second aspect is their intensivefocus on streams in the greater Balti-more area. In this rapidly urbanizingregion, they found a logarithmic rela-tionship between the proportion ofpavement in a watershed and the meanannual Cl concentration in streams.Above 15% impervious cover, Cl con-centrations were strong enough todamage some plants, and, above 40%,the streams crossed the threshold of250 mg�liter�1 Cl. Maximum winterconcentrations reached �4,600mg�liter�1 Cl, approximately one-quarter of the amount in seawater.

Not surprisingly, the data of Kaushalet al. (3) show strong seasonal effects,with the highest concentrations in win-ter. More surprisingly, Cl concentrationsin the rural streams did not return tobaseline levels in summer, even when nosalt was being applied. One reason isthat salt concentrations build up overmany years and remain high in the soiland groundwater. Groundwater seepinginto streams often keeps water flowingduring the driest periods, typically insummer. If the groundwater is salty, thestream will be salty. Increases ingroundwater salinity have indeed been

observed in the northeastern U.S. andCanada (11, 12). For example, a surveyof 23 springs in the greater Torontoarea found Cl concentrations topping1,200 mg�liter�1 arising from road saltuse (11). This groundwater salinity isthe primary concern for long-term pota-ble water supply. Once groundwaterbecomes salty, it typically will take de-cades to centuries for the salts to disap-pear, even when road salt use ends.

Where Is the Sodium?The current study focused on the fate ofCl, providing clear evidence of its linkto road salt and build-up in streams.Two unanswered questions are (i) howthe road salt gets into the streams and(ii) what happens to the accompanyingsodium (Na). Na is important for itshealth effects on wildlife and peopleand also as a biogeochemical tracer. Ifroad salt takes a fairly direct path to

See companion article on page 13517 in issue 38 of volume102.

†To whom correspondence should be addressed at: Depart-ment of Biology, Box 91000, Duke University, Durham,NC 27708-1000. E-mail: [email protected].

© 2005 by The National Academy of Sciences of the USA

Fig. 1. Sales of rock salt for highway use in the U.S. from 1940 to 2004 in millions of metric tons (Mg) (1,2). The dashed line denotes our estimate of the calculated annual wet deposition of Na and Cl in the U.S.,derived primarily from sea salt. The amount of Na and Cl in road salt topped Na and Cl deposition for thecontinental U.S. some time in the early 1960s. We estimated U.S. wet deposition of NaCl based on datafrom 1999–2003 using deposition isopleth maps from ref. 15. The product of mean area and depositionrates for each isopleth interval was calculated by state and summed. For Na and Cl, rates of dry depositionshould be smaller than rates of wet deposition.

www.pnas.org�cgi�doi�10.1073�pnas.0507389102 PNAS � October 11, 2005 � vol. 102 � no. 41 � 14487–14488

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streams through surface runoff or drain-age systems, the amounts of Na and Clreaching the streams should be roughlysimilar (0.65:1 mass ratio). If instead thedominant flow path involves under-ground transport through soils, where Clanions are more mobile than Na cations,then the ratio of Na to Cl will be lower.Na will gradually displace Ca, Mg, K,and protons in the soil, altering soil fer-tility and uncoupling the flow of Nafrom Cl (13). We suggest that the ratioof changes in Na and Cl concentrationsover time in the stream waters describedby Kaushal et al. (3) could help deter-mine the importance of surface vs.underground pathways of road salttransport to streams. Lower Na:Cl ratioswould suggest proportionally greaterfluxes through soil.

Human Use Versus Natural DepositionTo understand how much rock salt isnow being applied in the U.S., we com-pared the amount to estimated naturaldeposition rates of Na and Cl. In 1940,sales of rock salt for highway use wereonly 149,000 Mg (Fig. 1). Today, thevalue is a hundred times higher, �18million Mg. This amount dwarfs our cal-culated estimate for natural wet deposi-tion of Na and Cl for the continentalU.S. each year, 2.2 Mg�yr�1 derived pri-marily from sea salt (Fig. 1).

Most of the �18 million Mg of NaClused on roads each year is applied innortheastern and midwestern states,with six states using three quarters ofthe total: New York, Ohio, Michigan,Illinois, Pennsylvania, and Wisconsin.On a statewide basis, applications of deic-ing salt are 200 kg�ha�1�yr�1 for NewYork and Ohio and 400 kg�ha�1�yr�1 inthe District of Columbia (14). In rural

states, such as Vermont, salt loads are still136 kg�ha�1�yr�1 (14). Focusing just on Cl,the average input from road salt in Ver-mont is therefore 80 kg�ha�1�yr�1, twoorders of magnitude higher than esti-mated atmospheric Cl inputs of 0.88kg�ha�1�yr�1 (1999–2003 average; ref. 15).

The increases are equally large forNa, a cation that is often abundant inrocks but tends not to be retained asmuch as other cations in soils (16). Anaverage Vermont forest soil receiving anannual Na load of 50 kg�ha�1 from rocksalt has the potential to displace othercations and load its entire exchangeable

complex with Na in the top 10 cm ofthe soil in 80 years [based on an effec-tive cation exchange capacity of 15 mil-liequivalents (meq)�100 g of soil and abulk density of 1.2 g�cm3]. Obviously,rock salt is not applied evenly across astate; some areas will have higher inputsand other areas will have lower or noinputs. The key point is that, comparedwith natural deposition of Na and Cl,inputs of road salt are now enormous,and water moves that salt around lo-cally and regionally as Kaushal et al. (3)highlight.

The most difficult aspect of road saltuse is knowing what to do about it.

Kaushal et al. (3) do not discuss policysolutions or suggest alternatives to itsuse. Scandinavian countries are studyingalternatives to traditional road salt, in-cluding mixing it with sand or sugar andreplacing it with other chemicals, suchas potassium formate. Canada took thecontroversial step in 1995 of placing salton its Priority Substances List for assess-ment under the Canadian EnvironmentalProtection Act, and, in 2004, it released aCode of Practice for the EnvironmentalManagement of Road Salts. Concernsfor drinking water quality in New Yorkhave led some cities to use chemical al-ternatives, including potassium acetate(C2H3KO2) and calcium magnesium ace-tate (CaxMgy(C2H3O2)2(x�y)) (17). How-ever, these chemicals are an order ofmagnitude more expensive than NaCl.The beauty of road salt is that it workswell and is cheap.

In summary, no one is suggesting thatsociety should instantly ban rock saltuse. Nonetheless, the results of Kaushalet al. (3) do suggest that there are real,long-term consequences to its use, par-ticularly for freshwater systems andsoils. Understanding which environ-ments are more likely to transfer saltfrom roads, streams, and groundwatercould help managers identify sensitivespecies and highway segments that needalternative methods of deicing. Moregenerally, a prudent step would be toadopt a ‘‘less is more’’ policy, reducingthe amounts of salt applied and consid-ering alternatives where economicallyfeasible. As is so often the case today,society is left to balance a discrete,positive benefit (safer roads) with moredilute environmental costs that buildover decades and take decades to re-cover (18).

1. Ewell, M. E. (2003) Mining and Quarrying Trends2003 (U.S. Geological Survey, U.S. Department ofthe Interior, Washington, DC).

2. The Salt Institute (2004) Salt Mining Statistics (TheSalt Institute, Alexandria, VA).

3. Kaushal, S. S., Groffman, P. M., Likens, G. E.,Belt, K. T., Stack, W. P., Kelly, V. R., Band, L. E.& Fisher, G. T. (2005) Proc. Natl. Acad. Sci. USA102, 13517–13520.

4. Peters, N. E. & Turk, J. T. (1981) Water Resour.Bull. 17, 586–598.

5. Siver, P. A., Canavan, R. W., Field, C. K., Marsi-cano, L. J. & Lott, A. M. (1996) J. Environ. Qual.25, 334–345.

6. Godwin, K. S., Hafner, S. D. & Buff, M. F. (2003)

Environ. Pollut. 124, 273–281.7. Forman, R. T. T. & Alexander, L. E. (1998) Annu.

Rev. Ecol. Syst. 29, 207–231.8. Howard, K. W. F. & Haynes, J. (1993) Geosci. Can.

20, 1–8.9. Wegner, W. & Yaggi, M. (2001) Stormwater 2, No. 5.

10. Thunqvist, E. L. (2004) Sci. Total Environ. 325,29–37.

11. Williams, D. D., Williams, N. E. & Cao, Y. (2000)Water Res. 34, 127–138.

12. Foos, A. (2002) Environ. Geol. 44, 14–19.13. Norrstrom, A. C. & Bergstedt, E. (2001) Water Air

Soil Pollut. 127, 281–299.14. Kostick, D. S. (1993) Bureau of Mines Informa-

tion Circular 9343 (Bureau of Mines, U.S.

Department of the Interior, Washington, DC).15. Illinois State Water Survey, NADP Office (2005)

National Atmospheric Deposition Program-NationalResearch Support Program-3 Report (Illinois StateWater Survey, NADP Office, Champaign, IL).

16. Jobbagy, E. G. & Jackson, R. B. (2001) Biogeo-chemistry 53, 51–77.

17. National Research Council (1991) Highway Deic-ing: Comparing Salt and Calcium Magnesium Ac-etate (Transportation Research Board, Washing-ton, DC), Report 235.

18. Jackson, R. B., Carpenter, S. R., Dahm, C. N.,McKnight, D. M., Naiman, R. J., Postel, S. L. &Running, S. W. (2001) Ecol. Appl. 11, 1027–1045.

There are real, long-term consequencesto rock salt’s usefor freshwater

systems and soils.

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____________________________________________________________________________________ Snow, Road Salt and the Chesapeake Bay 1

Snow, Road Salt and the Chesapeake Bay By Tom Schueler, Center for Watershed Protection We can soon expect our annual doses of wintry weather, with the inevitable snow and ice storms. On average, we can expect measurable snowfall, sleet, or freezing rain just under twenty days a year. Even a small amount of wintry weather can create headaches for commuters who drive along the 200,000 mile network of roads that connect communities across the Chesapeake Bay. It is not surprising that local and state highway agencies make Herculean efforts to quickly remove snow and ice from roads and freeways so our society can keep moving. Increasingly, they rely heavily on salt, sand and other deicers to keep roads open and safe. This article examines what happens to the salts and other chemicals applied to the roads and what is known about their impact on the environment. Road Salt Applications Road salting is a pretty recent phenomenon in our region. Prior to the 1970's, sand and other abrasives were the primary weapon of choice to attack snow and ice. With the advent of new spreaders and increased road traffic, most highway agencies shifted toward heavier use of road salt in the winter. Annual road salt use has gradually increased over the last two decades, and . now fluctuates between 10 and 20 million tons per year on a nationwide basis, depending on the severity of the winter. Despite the fact that much of the Chesapeake Bay watershed is situated below the traditional “snow-belt”, it still accounts much of the road salt used in the country (About a third of all road salt used in the U.S. is applied to states in the mid-Atlantic region). In our region, about 20 tons of road salt are applied to each mile of four lane highway, in a normal year. While exact statistics are not available for the total amount of road salt used across the Chesapeake Bay watershed, we conservatively estimate that about 2.5 million tons are applied each year. This is a lot of salt. To put this in perspective, consider that if it all this salt were dissolved in a container of fresh water, it would make more than 15 billion gallons of seawater. Or to put it another way, the entire volume of the tidal Chesapeake Bay (51 billion cubic meters) typically contains about 250 million tons of chloride at any given time. Salt drives the Chesapeake Bay The Chesapeake Bay is an estuary, which means that it is influenced both by the freshwater from its tributary rivers and salt water from the ocean. Indeed, it is the contrast between the two types of water that drives the circulation of the Chesapeake Bay. Ocean water has a salinity of about 35 parts of salt per thousand parts of water. Freshwater, on the other hand, has less than 50 parts of salt per million parts of waters. Consequently, when the denser ocean water enters the mouth of Bay, it tends to sink and creep along the bottom of the Bay. Fresh water is much more buoyant as it enters from the top of the Bay, and tends to travel along the top of the Bay. Throw in the tides, some wind, and the rotation of the earth, and the basic circulation of the Chesapeake Bay is created The presence of so much salt is a major reason why the surface of the Chesapeake Bay rarely freezes over in the winter months, and can never freeze completely solid.

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When the Snow Melts, Streams Get Salty Chloride is one of the main components of road salt, and is extremely soluble in water. As a result, there is virtually no way to remove chloride once it gets into the watershed. It moves freely and easily through both surface and groundwater on its way to the Bay. Indeed, road salting is thought to be the primary source of chlorides to streams and rivers of the Bay. Consequently, once snow melts, streams tend to get salty. The highest chloride levels are recorded in melt-water runoff near salt depots, major highways, snow piles in parking lots, local streets and in urban streams, as shown below: Salt storage areas 50,000 to 80,000 mg/l Highway melt-water runoff 5000 to 20,000 mg/l Snow piles in parking lots 5000 to 15,000 mg/l Street melt-water runoff 2000 to 4000 mg/l Urban streams in winter 1500 to 2500 mg/l Normal Freshwater 20 to 50 mg/l Ocean Water 25,000 to 30,000 mg/ l In addition, road salt contains many impurities. As much of 2 to 5% of road salt consists of other elements, such as phosphorus, nitrogen, copper and even cyanide. A form of cyanide is added to road salt as anti-caking agent (about 0.01% dry weight). Under certain conditions, it can be transformed into free cyanide, which can be very harmful to humans and aquatic life. As much as two pounds of cyanide are deposited on a mile of four-lane highway through normal road salting concentrations. Scientists have measured cyanide levels in urban streams ranging from 3 to 270 parts per billion (ppb) for short periods of time as a result of road salting (toxicity begins at 20 ppb). Melting Snowpacks: Not Exactly Pure as the Driven Snow Fresh snow is beautiful and relatively pure. In a short time, however, the snow pack gets grey and dirty in urban areas, particularly along the roadside. Road slush, salt spray, airborne pollutants, street dirt, and trash all accumulate in the snow pack over days and weeks. When the snow pack melts, it releases many pollutants to the stream, including sediments, nutrients, zinc, copper, lead and hydrocarbons and chloride. During the melt, pollutant concentrations in storm water runoff are among the highest seen all year. Impacts of road salt on the environment Generally, the presence of chlorides in our drinking water is not a major public health concern. Our tongues can generally detect saltiness or brackishness in drinking water when chloride levels exceed 250 mg/l. Water utilities routinely report a peak in complaints about the taste of drinking

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water during winter melt events. However, since we only get about 2% of our daily salt intake from drinking water, the extra sodium and chloride are not usually a major problem. We get about 98% of the salt from the foods we eat, so it makes more sense to pass on the french fries, rather than a glass of water. The impacts of chloride and melt-water pollution on aquatic life, however, can be much more severe. A growing body of research has lead Canada to recently designate road salt as an environmental toxin, and look for ways to reduce its use without compromising road safety. So, what are the impacts associated with chlorides in the environment? To start with, chloride can be harmful to many forms of aquatic life at concentrations of about 1000 mg/l. Chloride levels above this level are not uncommon in many small streams and wetlands, at least for short periods of time in the winter. A growing body of research has documented the strong impacts of chlorides on stream, lake and wetland ecosystems in the snow-belt states, but few studies have examined these impacts in the mid-Atlantic states. Melting roads create an artificial “salt lick” that attracts both birds and mammals. In the past, natural salt licks were often considered the best hunting grounds since wildlife crave salt in their diet. Wildlife biologists have recently observed that deer, elk, moose and other mammals lick slat from road-sides where the often become road-kills. The same effect is seen for small birds, such as finches, whose cravings for roadside salt have earned them the dubious nickname as “grill birds” in northern regions of the country. Salting the Earth When the Romans finally defeated Carthage in the Punic Wars, they did not just settle for plundering and razing the city, and killing or enslaving its inhabitants. To ensure that Carthage could never again become a rival, they reputedly salted the fields of Carthage so crops could not grow. Whether (and how) the Romans salted the earth is still a matter of debate among archaeologists, but it is very clear that high salt levels can be very harmful to plants. High salt levels are frequently measured in roadside soils. The saltiest soils occur within a few feet from the blacktop, but the influence of salt can extend as far as 100 feet from a major highway and 50 feet from a two-lane road (salt is transported by spray from fast moving cars and trucks). High salt levels are usually observed in lawn soils within five or ten feet of sidewalks and driveways that are salted. Many species of trees, shrubs and ground covers are extremely sensitive to high soil chloride levels, and may be killed, dieback or fail to germinate under these conditions (see the list in Low Salt Diet section). Indeed, highway researchers report that as may as ten percent of trees found along road corridors have been harmed by road salt. On the other hand, some plant species flourish in soils with high chloride levels. Two notable examples are cattails and Phragmites, two hardy wetland plants that have become ubiquitous in roadside swales and wetlands. Indeed, Phragmites is a invasive plant that prefers brackish water. A researcher has claimed that Phragmites has migrated from the east coast to the Midwest by following the salty soils of the New York thruway system. Excessive road salt also damages human infrastructure, including concrete bridges decks and

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parking structure and corrosion of metal surfaces (such as the undersides of older cars). The Transportation Research Board estimates that the national cost of these damages exceeds four billion dollars each year. Towards a Low Salt Diet The road salting that keeps us moving in the winter clearly has a large economic and environmental cost. To date, no cost-effective alternative to road salting has emerged, although research efforts are continuing to evaluate some promising candidates. Highway agencies have begun to take the salt problem seriously, and are working hard to develop new technology to reduce its environmental impact. Examples include the construction of salt domes to safely store salt, use of calibrated spreaders to apply the right dose, improved driver training, more sophisticated forecasting methods to treat roads at the proper time and the designation of low salt application zones near environmentally sensitive areas. Homeowners can also make better choices in how they use de-icing chemicals, and a series of practical tips are given in the Low Salt Diet section. What You Can Do: Put your sidewalk and driveway on a low salt diet Keeping ice and snow off your driveway and side walks is important for safety. The following tips can help you choose the best deicing product for your home and the environment. 1. Buy early. Make sure to buy your deicing product well before the big storm hits, otherwise you will be looking at empty shelves, and have few, if any, environmental choices to make at the store. 2. Check the label. The table below provides a summary of the pros and cons of main ingredients of common de-icing products. Check the package closely to see what the look closely to see what your buying. I recommend using calcium chloride over sodium chloride (rock salt)

Check the Label For Works Down to : Cost Environmental Risks

Calcium Magnesium Acetate (CMA)

22 to 25 degrees F 20 times more than rock salt

Less toxic

Calcium Chloride -25 degrees F 3 times more than rock salt

Uses lower doses No Cyanide Chloride impact

NaCl: Sodium Chloride, also known as rock salt

15 degrees F about 5 bucks for a 50 pound bag

Contain cyanide Chloride impacts

Urea 20 to 25 degrees F 5 times more than rock salt

Needless nutrients Less Corrosion

Sand No melting effect about 3 buck for a 50 lb bag

Accumulates in streets and streams

3. Avoid kitty litter and ashes. Although these products are environmentally friendly, they don’t work. While they provide some traction, they do not melt snow and ice. Also, they tend to get real gooey and messy when it warms up, which often causes tracking on the floors of your home. If

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traction is what you want, then stick with sand, which is much cheaper and easier to sweep up. 4. Shovel early and often. When it comes to snow removal, there is no substitute for muscle and elbow grease. Deicers work best when there is only a thin layer of snow or ice that must be melted. So get out the snow shovel and move as much snow as you can during the storm if possible. A flat hoe can also help to scrape ice off the surface before any deicers are applied. 5. Know Your Salt-Risk Zone. You wouldn’t want to kill your favorite tree, shrub or grass, so check out the plants that grow within five or ten feet of your driveway and sidewalk (and the road, for that matter). The table below summarizes some of salt sensitive plants that might be at risk. If you have salt-sensitive tree, shrub or grass in this zone, you should avoid any de-icing product that contains chlorides (rock salt and calcium chloride), or use very small doses. You may want to use CMA as a safer alternative, or stick with sand for traction.

Landscaping Areas Species at Risk from Salting

Deciduous Trees

Tulip polar, Green ash, Hickory, Red maple, Sugar Maple

Conifers

Balsam fir, White pine, Hemlock, Norway Spruce

Shrubs Dogwood, redbud, hawthorn, rose, spirea

Grasses Kentucky bluegrass, Red fescue

6. Avoid Products that Contain Urea. Some folks recommend the use of urea as a safer alternative, reasoning that it does not contain chlorides and, as a form of nitrogen, will help fertilize your yard when it washes off. In reality, urea-based deicing products are a poor choice. To begin with, urea is fairly expensive and performs poorly when temperatures drop below 20 degrees F. More to the point, the application rate for urea during a single deicing is ten times greater than that needed to fertilize the same area of your yard. Of course, very little of the urea will actually get to your lawn, but will end up washing into the street and storm drain. Given that nitrogen is a major problem in the Bay, it doesn’t make sense to use nitrogen-based products for de-icing 7. Apply salt early, but sparingly. As Mom always told you, a little salt goes a long way. The recommended application rate for rock salt is about a handful per square yard treated (after you have scraped as much ice and snow as you can). Throwing any more salt down won’t speed up the melting process. Even less salt is needed if you are using calcium chloride (about a handful for every three square yards treated – or about the area of a single bed). If you have a choice, pick calcium chloride over sodium chloride. Calcium chloride works at much lower temperatures and is applied at a much lower rate. Links National Snow and Ice Data Center: www.nsidc.org Salt Institute: www.saltinstitute.org

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Polluted Runoff (Nonpoint Source Pollution) Recent Additions | Contact Us | Search: EPA Home > Water > Wetlands, Oceans, & Watersheds > Polluted Runoff (Nonpoint Source Pollution) > Controlling (NPS) Runoff from Roads, Highways and Bridges

Controlling Nonpoint Source Runoff Pollution from Roads, Highways and Bridges EPA, Office of Water, August 1995 (EPA-841-F-95-008a)

Roads, highways, and bridges are a source of significant contributions of pollutants to our nation's waters. Contaminants from vehicles and activities associated with road and highway construction and maintenance are washed from roads and roadsides when it rains or snow melts. A large amount of this runoff pollution is carried directly to water bodies.

Contaminants in Runoff Pollution Runoff pollution is that associated with rainwater or melting snow that washes off roads, bridges, parking lots, rooftops, and other impermeable surfaces. As it flows over these surfaces, the water picks up dirt and dust, rubber and metal deposits from tire wear, antifreeze and engine oil that has dripped onto the pavement, pesticides and fertilizers, and discarded cups, plastic bags, cigarette butts, pet waste, and other litter. These contaminants are carried into our lakes, rivers, streams, and oceans.

Contaminants in runoff pollution from roads, highways, and bridges include: Sediment: Sediment is produced when soil particles are eroded from the land and transported to surface waters. Natural erosion usually occurs gradually because vegetation protects the ground. When land is cleared or disturbed to build a road or bridge, however, the rate of erosion increases. The vegetation is removed and the soil is left exposed, to be quickly washed away in the next rain. Erosion around bridge structures, road pavements, and drainage ditches can damage and weaken these structures.

Soil particles settle out of the water in a lake, stream, or bay onto aquatic plants, rocks, and the bottom. This sediment prevents sunlight from reaching aquatic plants, clogs fish gills, chokes other organisms, and can smother fish spawning and nursery areas.

Other pollutants such as heavy metals and pesticides adhere to sediment and are transported with it by wind and water. These pollutants degrade water quality and can harm aquatic life by interfering with photosynthesis, respiration, growth, and reproduction.

Oils and Grease: Oils and grease are leaked onto road surfaces from car and truck engines, spilled at fueling stations, and discarded directly onto pavement or into storm sewers instead of being taken to recycling stations. Rain and snowmelt transport these pollutants directly to surface waters.

Heavy Metals: Heavy metals come from some "natural" sources such as minerals in rocks, vegetation, sand, and salt. But they also come from car and truck exhaust, worn tires and engine parts, brake linings, weathered paint, and rust. Heavy metals are toxic to aquatic life and can potentially contaminate ground water.

Note: This information is provided for reference purposes only. Although the information provided here was accurate and current when first created, it is now outdated.

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Debris: Grass and shrub clippings, pet waste, food containers, and other household wastes and litter can lead to unsightly and polluted waters. Pet waste from urban areas can add enough nutrients to estuaries to cause premature aging, or "eutrophication."

Road Salts: In the snowbelt, road salts can be a major pollutant in both urban and rural areas. Snow runoff containing salt can produce high sodium and chloride concentrations in ponds, lakes, and bays. This can cause unnecessary fish kills and changes to water chemistry.

Fertilizers, Pesticides, and Herbicides: If these are applied excessively or improperly, fertilizers, pesticides, and herbicides can be carried by rain waters from the green parts of public rights-of-way. In rivers, streams, lakes, and bays, fertilizers contribute to algal blooms and excessive plant growth, and can lead to eutrophication. Pesticides and herbicides can be harmful to human and aquatic life.

Recognizing and Controlling Runoff Pollution Erosion gullies on land cleared of vegetation at a road construction site are a sign of sediment runoff. Iridescence (rainbow colors) in runoff water is a sign of spilled petroleum products washing off roads. Other signs of runoff pollution during road construction include obvious changes in streams or rivers downstream from the construction, such as bank erosion and sloughing, muddy or oily water, and sandbar relocation. Clumps of mud on roads leaving a construction site can lead to sediment flows heading for drainage ditches and storm inlets that empty into nearby streams.

Rad projects should incorporate pollution prevention , preferably by reducing the amount of pollutants released, into an effective runoff pollution control plan.

Best management practices such as permanent storm water retention/detention ponds, slope protection, or grass strips, and temporary sediment traps, silt fences, diversion trenches, and provisions for washing vehicles before they leave the construction site are all means to reduce runoff pollution.

Pollution Prevention and Control Programs and Regulations The need to protect our environment has resulted in a number of pollution control laws, regulations, and programs. The implementation of these programs takes place at all levels - federal, state, and local.

Clean Water Act In 1987, Congress established the Nonpoint Source Management Program under section 319 of the Clean Water Act (CWA), to help states address nonpoint source, or runoff pollution by identifying waters affected by such pollution and adopting and implementing management programs to control it. These programs recommend where and how to use best management practices (BMPs) to prevent runoff from becoming polluted, and where it is polluted, to reduce the amount that reaches surface waters.

Coastal Zone Management Act and Reauthorization The Coastal Zone Management Act of 1972 established a program for states and territories to voluntarily develop comprehensive programs to protect and manage coastal water resource.

There are now 29 states and territories with federally approved coastal zone management programs.

The Coastal Zone Act Reauthorization Amendments (CZARA) of 1990 specifically charged the coastal states and territories with developing upgraded programs to protect coastal waters from runoff pollution. This program is administered nationally by the Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration (NOAA). CZARA applies to construction sites in 29 states and territories where less than 5 acres is disturbed. CZARA also applies to storm water runoff from roads that is carried by municipal separate storm sewer systems that serve populations of less than 100,000.

National Pollution Discharge Elimination System Construction sites where 5 or more acres are disturbed are considered point sources of pollution and require a National Pollutant Discharge Elimination System (NPDES) storm water permit under section 402 of the CWA. In addition. the following types of storm water discharges are regulated under the NPDES permit program: discharges from municipal separate sewer systems serving populations of 100,000 or more; discharges associated with industrial activities, including construction sites of 5 acres or more; and



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other discharges identified by EPA or a state as needing an NPDES permit because they contribute to a water quality violation.

EPA is developing regulations for other storm water discharges, which may include discharges from municipal separate storm sewer systems serving populations of less than 100,000 and discharges associated with commercial operations, light industries, and construction sites of less than 5 acres. If and when construction sites of less than 5 acres are regulated under the NPDES program, they will no longer besubject to the requirements of CZARA.

Intermodal Surface Transportation Efficiency Act A major piece of legislation designed to expand and improve the quality and condition of our national highway and transportation systems is the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, better known as "ice tea." This act contains provision for the planning and developing of highway systems and a host of transportation enhancements activities including the mitigation of water pollution due to highway runoff.

Through ISTEA, states are able to use a portion of their federal funding allotment for runoff pollution control devices and other BMPs to prevent polluted runoff from reaching their lakes, rivers, and bays.

Other EPA Programs Other EPA programs that help control roadway pollution include the National Estuary Program (NEP) established by the CWA and the pesticides program under the Federal Insecticide, Fungicide and Rodenticide Act. The NEP focuses on point sources and runoff pollution in targeted, high-priority estuaries. The pesticides program regulates pesticides that might threaten ground and surface waters.

Management Measures and Best Management Practices CZARA established goals to be achieved in controlling the addition of pollutants to out coastal waters. EPA developed a Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters. States with approved coastal zone management programs are required to incorporate the Guidance management measures, or more stringent management measures, into their Coastal Zone Nonpoint SourceControl Programs. CWA section 319 programs assist states in the development of nonpoint source controls.

Key management measures for roads, highways, and bridges include the following:

Protect areas that provide important water quality benefits or are particularly susceptible to erosion or sediment loss. Limit land disturbance such as clearing and grading and cut fill to reduce erosion and sediment loss. Limit disturbance of natural drainage features and vegetation. Place bridge structures so that sensitive and valuable aquatic ecosystems are protected. Prepare and implement an approved erosion control plan. Ensure proper storage and disposal of toxic material. Incorporate pollution prevention into operation and maintenance procedures to reduce pollutant loadings to surface runoff. Develop and implement runoff pollution controls for existing road systems to reduce pollutant concentrations and volumes.

Consult the Guidance for detailed information on the management measures.

Management measures, as a practical matter, can often be achieved by applying best management practices appropriate to the source of runoff, runoff location, and climate. The Guidance suggests a number of best management practices that are options for states to use in successfully achieving management measures for bridges, road construction, road maintenance, and operation.

Examples of best management practices for roads, highways, and bridges include:

Avoid highway locations that require numerous river or wetland crossings (to achieve the Management Measure for Bridges).



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Coordinate erosion and sediment controls with the Federal Highway Administration (FHWA), the American Association of State Transportation Officials (AASHTO), and state guidelines (to achieve the Management Measure for Construction Projects). Collect and remove road debris and repair potholes (to achieve the Management Measure for Operation and Maintenance).

For More Information To obtain more information on the Clean Water Act, runoff (nonpoint source) pollution control programs, CZARA, storm water regulations and control, ISTEA, or management measures and BMPs for roads, highways, and bridges, contact the appropriate offices listed below.

United States Environmental Protection Agency Nonpoint Source and NPDES Storm Water Coordinators:

U.S. EPA Region I (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont) NPS (617) 565-3513 NPDES Storm Water (617) 565-3580 U.S. EPA Region II (New Jersey, New York, Puerto Rico, Virgin Islands) NPS (212) 637-3701 NPDES Storm Water (212) 637-3724 U.S. EPA Region III (Delaware, Maryland, Pennsylvania, Virginia, West Virginia) NPS (215) 597-3429 NPDES Storm Water (215) 597-0547 U.S. EPA Region IV (Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee) NPS (404) 346-2126 NPDES Storm Water (404) 347-3012 U.S. EPA Region V (Illinois, Indiana, Michigan, Minnesota, Ohio, Wisconsin) NPS (312) 886-0209 NPDES Storm Water (312) 886-6100 U.S. EPA Region VI (Arkansas, Louisiana, New Mexico, Oklahoma, Texas) NPS (214) 665-7140 NPDES Storm Water (214) 665-7175 U.S. EPA Region VII (Iowa, Kansas, Missouri, Nebraska) NPS (913) 551-7475 NPDES Storm Water (913) 551-7418 U.S. EPA Region VIII (Colorado, Montana, North Dakota, South Dakota, Utah, Wyoming) NPS (303) 293-173 NPDES Storm Water (303) 293-1630 U.S. EPA Region IX (Arizona, California, Hawaii, Nevada) NPS (415) 744-2011 NPDES Storm Water (415) 744-1906 U.S. EPA Region X (Alaska, Idaho, Oregon, Washington) NPS (206) 553-4181 NPDES Storm Water (206) 553-8399 U.S. EPA Headquarters NPS (202) 260-7100 NPDES Storm Water (202) 260-9541 Chesapeake Bay Program (800) 968-7229 Gulf of Mexico Program (601) 688-7940

Federal Highway Administration Local Transportation Assistance Program (LTAP) Technology Transfer (T2) Centers:

The LTAP program provides training and technical assistance to local/tribal government transportation agencies on roads and bridges. For the location of the LTAP T2 center in your state, contact the T2 Clearinghouse at (202) 347-7267.

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Polluted Runoff (Nonpoint Source Pollution)Recent Additions | Contact Us | Search: EPA Home > Water > Wetlands, Oceans, & Watersheds > Polluted Runoff (Nonpoint Source Pollution) > Planning Considerations for Roads, Highways and Bridges

Planning Considerations for Roads, Highways and Bridges

The Coastal Zone Act Reauthorization Amendments (CZARA) of 1990 established goals to be achieved for the prevention and control of runoff pollution to our coastal waters. The Environmental Protection Agency

United States Environmental Protection

Agency

Office of Water (4503F)

EPA-841-F-95-008bOctober 1995

(EPA) published Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters, which identifies management measures and best management practices for nonpoint source (NPS) pollution control.

Our roads, highways and bridges can be a source of a significant amount of pollution to our nation's water. Pollution is generated during road construction, maintenance, and use. Nonpoint source pollution, or runoff pollution, is created when chemicals, debris, fertilizers, automotive oils, debris from wearing parts, and litter are washed off roadways and bridges during rainstorms and carried as runoff to streams, rivers, lakes and bays.

There are many opportunities available to prevent and control runoff pollution by applying management measures and best management practices during the planning, construction, and operation and maintenance of highway systems. Management measures are achieved by applying best management practices appropriate to the source of runoff, climate, and average daily traffic volume. Planning considerations to help control runoff pollution from roads, highways, and bridges are discussed in this fact sheet.

Road, Highway and Bridge Planning

Poor planning can contribute to pollution problems. Wetlands and vegetated areas near waterbodies can be damaged by construction, decreasing the water quality benefits that they normally provide. Areas susceptible to erosion, such as steep slopes or land with loose soil, can be disturbed, causing increased sedimentation flows into receiving streams.

As plans are developed for new roads, highways and bridges, or for reconstructing existing facilities, best management practices to help reduce the volume and concentration of erosion and sedimentation produced by the project should be incorporated into project design.

The following are some pollution prevention techniques that can be incorporated into highway planning and

Page 1 of 5Planning Considerations for Roads, Highways and Bridge | Polluted Runoff (Nonpoint So...


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design:

� Evaluate alternatives for incorporating a road system or bridge into the natural characteristics of the site. Analyze environmental features, such as topography, drainage patterns, soils, climate, and existing land use. Natural drainage systems can be taken advantage of, clearing and grading can be minimized, natural vegetation and buffer areas can be preserved, and sensitive land and water areas that provide water quality benefits (e.g., wetlands, spawning waters, etc.) and areas susceptible to erosion and sedimentation can be avoided.

� Preserve corridors for highways well in advance of construction to be certain that roads are built where they are most suitably located in terms of environmental and economic considerations. Lack of advance planning can lead to locating roads wherever space is available, or not being able to build a road at all.

� Avoid building roads and bridges where they will impact riparian areas adjacent to surface waters and wetland areas. These vegetated areas provide enormous water quality benefits through their ability to filter pollutants out of water passing through them.

Road, Highway and Bridge Construction

Road, highway, and bridge construction and reconstruction generate runoff pollution by virtue of the sheer volume of earth that must be disturbed and topsoil that is removed during these activities. For example, roads built perpendicular to slopes rather than parallel to them cut across natural drainage lines and create excessive earth disturbance.

Planning for pollution prevention and control measures in advance of and during construction can help avoidthese and other future problems.

Erosion and Sediment Control

Develop a site-specific erosion and sediment control plan to minimize the impacts of runoff waters on construction activities.

A number of provisions to lessen the environmental impacts of road construction are specified in an erosion and sediment control plan, including measures to ensure that exposed working surfaces are kept to a minimum, silt fences and sediment traps are optimally placed to prevent sediment from reaching drainage systems, vehicles are washed when leaving a construction site to remove excess mud, and temporary exit/entry roads to construction sites are provided with a coarse rock surface to prevent the transfer of soil offsite where it will be washed into nearby drainage channels.

Chemical Use and Control

Store, handle and dispose of construction site chemicals such as herbicides, insecticides, oils, gasoline, degreasers, antifreeze, concrete and asphalt products, sealers, paints, and wash water associated with these products to minimize their entry into runoff. One way to do this is to provide specific areas where these products are frequently used, such as fueling areas and equipment washing areas. This can help prevent dangerous chemicals from entering surface waters. This measure also applies to proper storage of road deicing materials.

Nutrient Use and Control

Fertilizers used to promote the growth of vegetation on disturbed earth can contribute excessive nitrates and phosphates to surface waters if overused. To ensure safety, a person knowledgeable of and certified for soil testing and nutrient application should be involved to determine the proper amount of fertilizer to apply in a given situation and the proper timing of applications to maximize their delivery to growing plants and minimize their entry into runoff.



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Road, Highway and Bridge Operation and Maintenance

Road, highway, and bridge operation and maintenance involve inspection, routine and season-specific maintenance, and repair of not only highways and bridges but also the rights-of-way where drainage control facilities are located. The following are examples of some maintenance activities that provide opportunities to prevent and control runoff pollution:

Inspection and General Maintenance

� Develop an inspection program and schedule to ensure that general maintenance is performed. Inspect erosion and sediment control devices regularly.

� Maintain retaining walls and pavements to minimize cracks and leakage. � Repair potholes. � Maintain energy dissipaters and velocity controls to minimize runoff velocity and erosion. � Properly dispose of accumulated sediment collected from detention ponds, drainage systems, and

pollution control structures, and any wastes generated during maintenance operations, in accordance with appropriate local, state and federal regulations.

� Use techniques such as suspended tarps, vacuums or booms to prevent paint, solvents and scrapings from becoming pollutants during bridge maintenance.

� When blading gravel roads, take care to maintain a structurally sound surface while providing an adequate crown and drainage so that erosion or scattering of gravel are avoided.

� Develop an infrastructure safety inspection program in conjunction with general maintenance. � Keep drainage ditches free of debris.

Snow and Ice Control

� Cover salt storage piles and other deicing materials to reduce contamination of surface waters. Locate them outside the 100-year floodplain.

� Regulate the application of deicing salts to prevent oversalting the pavement. � Use trucks equipped with salt spreading calibration devices. � Use alternative deicing materials, such as sand or salt substitutes, where sensitive ecosystems

should be protected. � Prevent dumping of accumulated snow into surface waters or onto frozen water bodies.

Right-of-Way Maintenance

� Seed and fertilize, seed and mulch, and/or sod damaged vegetated areas and slopes. � Establish pesticide/herbicide use and nutrient management programs. � Restrict herbicide and pesticide use in highway rights-of-way to applicators certified under the

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to ensure safe and effective application. � Limit the use of chemicals such as soil stabilizers, dust palliatives, sterilants, and growth inhibitors to

the best estimate of optimum application rates. Try to avoid excess application and consequent intrusion of such chemicals into surface runoff.

� Regularly clean, reshape, and revegetate drainage ditches to ensure they perform as desired. Keep ditch slopes covered with vegetation or other material.

� Maintain shoulders, slopes and swales to assure their function and operation.



Snow and Ice Control

Cover salt storage piles and other deicing materials to reduce contamination of surface waters. � g p gLocate them outside the 100-year floodplain. y pRegulate the application of deicing salts to prevent oversalting the pavement. � g pp g pUse trucks equipped with salt spreading calibration devices. � q pp p gUse alternative deicing materials, such as sand or salt substitutes, where sensitive ecosystems�

should be protected. pPrevent dumping of accumulated snow into surface waters or onto frozen water bodies. �

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Road Cleaning and Debris Removal

� Sweep, vacuum and wash residential streets and parking lots. � Collect and remove road debris. � Encourage litter and debris control management. � Encourage development of Adopt-a-Highway programs.

Sources of Additional Information

United States Environmental Protection Agency Nonpoint Source and NPDES Storm Water Coordinators:

U.S. EPA Region I (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont) NPS (617) 565-4426, NPDES Storm Water (617) 565-3610

U.S. EPA Region II (New Jersey, New York, Puerto Rico, Virgin Islands) NPS (212) 637-3700, NPDES Storm Water (212) 637-3767

U.S. EPA Region III (Delaware, Maryland, Pennsylvania, Virginia, West Virginia) NPS (215) 597-9077, NPDES Storm Water (215) 597-6511

U.S. EPA Region IV (Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee) NPS (404) 347-2126, NPDES Storm Water (404) 347-2019

U.S. EPA Region V (Illinois, Indiana, Michigan, Minnesota, Ohio, Wisconsin) NPS (312) 353-2079, NPDES Storm Water (312) 353-2121

U.S. EPA Region VI (Arkansas, Louisiana, New Mexico, Oklahoma, Texas) NPS (214) 665-7135, NPDES Storm Water (214) 665-7170

U.S. EPA Region VII (Iowa, Kansas, Missouri, Nebraska) NPS (913) 551-7030, NPDES Storm Water (913) 551-7034

U.S. EPA Region VIII (Colorado, Montana, North Dakota, South Dakota, Utah, Wyoming) NPS (303) 293-1565, NPDES Storm Water (303) 293-1623

U.S. EPA Region IX (Arizona, California, Hawaii, Nevada) NPS (415) 744-1953, NPDES Storm Water (415) 744-2001

U.S. EPA Region X (Alaska, Idaho, Oregon, Washington) NPS (206) 553-4013, NPDES Storm Water (206) 553-0966

U.S. EPA Headquarters, Nonpoint Source Control Branch NPS (202) 260-7100, NPDES Storm Water (202) 260-9541

Federal Highway Administration Local Transportation Assistance Program (LTAP) Technology Transfer (T2) Centers:

This fact sheet is the second in a series being produced jointly by EPA and the American Public Works Association (APWA) to improve

knowledge about and efforts to control runoff pollution from roadways and road construction activities. Working together, we can maintain and

improve our roadway systems and protect our waters.



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Appendix B

Urban Subwatershed Restoration Manual No. 1

AN INTEGRATED FRAMEWORK TO RESTORE SMALL URBAN

WATERSHEDS Prepared by:

Tom Schueler Center for Watershed Protection

8390 Main Street, 2nd Floor Ellicott City, MD 21043

www.cwp.org www.stormwatercenter.net

Prepared for: Office of Water Management

U.S. Environmental Protection Agency Washington, D.C.

February 2005

Note: This 166 page reference is included on the CD that is in included in this report. The following images in this appendix summarize the basic concepts of the Impervious Cover Model (ICM). Chapter 3 in this reference addresses the physical alterations and changes to stream hydrology that are symptomatic of Mankiller Branch and Babcock Creek. Appendix A of this reference outlines the current research supporting the ICM, and points out that the ICM applies to small streams, from first to fourth order, with a contributing subwatershed area of less than 10 square miles.

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THE IMPERVIOUS COVER MODEL

• A simple urban stream classification system that contains three stream categories based on the percentage of impervious cover in a subwatershed.

As subwatershed imperviousness increases:

• Runoff increases because the area of rooftops and transportation systems is increased.

• Soil percolation decreases because pervious areas are reduced.

• Evaporation decreases because there is less time for it to occur when runoff moves quickly off impervious surfaces.

• Transpiration decreases because vegetation has been removed.

Sensitive subwatersheds: Less than 10% impervious cover‐‐ streams are close to natural predevelopment conditions.

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Degraded subwatershed: 11% to 25% impervious cover ‐‐Degradation of key stream attributes can be expected, ie. the more sensitive aquatic organisms will disappear.

Nonsupporting subwatersheds:more than 25% impervious coverMay never recover predevelopment conditions no matter how many management practices are implemented.

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Streams with developed watersheds have substantially higher peak flows, and these peak flows occur more quickly than under predevelopment conditions.

This is reflective of typical urban conditions, where runoff moves quickly over impervious surfaces and drains into a channel.

Development and increased imperv ious cover also lead to erosion and undercutting of streambanks, widening of channels, and depositing of in‐channel sediment.

In addition, decreased base flow occurs in dry weather because a greater portion of runoff flows off the surface, resulting in less infiltration to ground water reserves.

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• Bankfull and subbankfull floods increase in magnitude and frequency.

• Dimensions of the stream channel are no longer in equilibrium with its hydrologic regime.

• Channels enlarge. • Stream channels are highly modified by human activity. • Upstream channel erosion contributes greater sediment load to the

stream. • Dry weather flow in the stream declines. • Wetted perimeter of the stream declines. • Instream habitat structure degrades. • Large woody debris (LWD) is reduced. • Stream crossings and potential fish barriers increase. • Riparian forests become fragmented, narrower, and less diverse. • Water quality declines. • Summer stream temperatures increase. • Reduced aquatic diversity.

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