Risk Assessment of Disposal Options for Street Debris and Detention Basin Sediments

Presented by

Matthew Looft Kendall Clare McPeters

Danielle RoySarah UllmanLara Vowles

Project Background

• Winooski has limited and costly collection techniques for street sweeping debris and catch basin sediments

• Interested in beneficial re-use alternatives for these sediments

Our Response…•Street debris and catch basin sediment analysis

•Alternatives for beneficial re-use that stress environmental integrity

•Case Studies of re-use successes •Simple effects

analysis of these alternatives

•Recommendations

Sample AnalysisWinooski and South Burlington comparison

of metal concentrations for Street Sweeping Debris

Metal

WinooskiSample

Concentration

(mg/kg)

S. Burlington Sample

Concentration Range

(mg/kg)

Computed MaximumTCLP

Concentration of S. BurlingtonSamples (mg/L)

RegulatoryTCLP

Concentration

(mg/L)

Arsenic 4.77 7.24 - 7.79 0.39 5

Barium 20.6 18.7 - 23.5 1.18 100

Cadmium < 1.13* < 0.771 - < 0.960 < 0.048 1

Chromium

15.7 17.6 - 24.3 1.22 5

Lead 23.7* 16.1 - 19.0 0.95 5

Mercury < 0.302 < 0.381 - 2.59 0.13 0.2

Selenium <3.22* < 1.10 - < 1.37 < 0.068 1

Silver <1.61* < 1.10 - < 1.37 < 0.068 5

Source: Pioneer Environmental Associates, LLC., ENDYNE, INC.

Sample Analysis Continuedtotal petroleum hydrocarbons (TPH)

TPH (mg/kg) TPH Maximum Allowable

Amounts (mg/kg or ppm)

Street Sweeping

Sediments

90.8 1,000

Catch Basin Sediments

82.6 1,000

Source: ENDYNE, INC., Vermont Agency of Natural Resources

Winooski TPH Concentrations and Regulatory Levels

Results of Sample AnalysesTPH and RCRA metal concentrations well below Vermont ANR Guidelines

for

Petroleum Contaminated Soil and Debris

Hazardous Waste Management Regulations

*Beneficial Re-Use Possible!

Possible Risks if Above ANR Guidelines

• TPH: Total Petroleum Hydrocarbons– Minimal exposure is unavoidable – Acute exposure can cause adverse

reactions in the blood, skin, eyes, legs (paralysis), immune system

– Can linger in soils, film on surface waters, or settle into bottom sediments

Possible Risks Continued…

• RCRA 8 Metals: arsenic, barium, cadmium, chromium, lead, mercury, selenium, silver– Bioaccumulation in plant and animal tissue– Threats to microorganisms in soil ecosystems– Severe allergic reactions– Carcinogenicity– Damaging effects to nervous system and/or

brain of fetuses– DNA damage

Environment and Human Health Risks

Alternative Reuses if Above ANR Guidelines

• Compost– Biologically decomposes organics– Thermal desorption of some volatile organics– Simple process (windrows, turning, wetting)– Valuable topsoil or mulch as end product

• Biological Degradation– Inoculating with soil bacteria, mycelial fungi to

enhance decomposition of pollutants and residues

Suggested Alternatives for Winooski

• “No action” – Continued disposal in landfills

• Daily cover at landfills• Compost additive• Road sand• Containment/absorption material • Roadway fill or backfill• Sub-fill for potholes• Replacement for raw material in concrete

or asphalt• Land reclamation

Case Studies

• Bloomington, MN: 100% reduction of landfilling sweepings by reusing as road sand

• Bangor, ME: reuse as clay composite for rec. trails

• Worcester, MA: development of guidelines for finding reuse alternatives (Chelsea Center)

• Colorado Springs, CO: 100% reduction of landfilled CB sediments by facility for dewatering, screening, composting

Reuse Initiatives

Possibility for an in depth study on beneficial reuse of street sweepings and catch basin sediments to happen at UVM to benefit the Burlington, Winooski, Williston communities?

Effect Analysis for Proposed Alternatives

  Environmental Economic Social

No action N P N

Landfill cover M N M

Recreation Trails P M P

Compost Additive N P P

Road Sand M P P

Contaminant/ Adsorption material P P M

Construction fills P P P

To fill in bodies of water N P N

Crash Attenuation barriers P P P

High Priority Roads Close to Water bodies

Legend

Rivers

Roads

Water bodies

Roads of Concern with a 12% or greater slope or within 500 Feet of Water Sources

0 490 980 1,470 1,960245Meters

North

Community Collaboration and Beyond…

SAND Model

• Sediment Accumulation Nexus District– Regional Collection Community Sediments

• Analysis• Shred/Sort• Wash• Screen• Storage

– Trade for credits– Sell to business or public

Beneficial Reuse• Reapplication for transportation use• Mixed with clay for recreational paths at

Gilbrook Park • Landfill daily/weekly cover for Chittenden

Solid Waste District• Compost additive at the Intervale• Roadway fill or backfill at construction

sites • Fill in crash attenuation barriers along

Interstate 89• Containment/absorption medium for

hazardous material spill response

On Site Remediation

• Composting– Biological decomposition of organics– Thermal desorption of volatile organics

• Biological Degradation– Nutrient cycling– Waste and residue decomposition– Detoxification of environmental pollutants

• Immobilization– Aggregates in concrete or asphalt

Recommendations

Beneficial Reuse will-Be more effective than current practices

-Pay for itself over time-Reduce ‘new sand’ by 90-100%

*Winooski should initiate a local beneficial reuse program to serve as an example for a county wide SAND program