Public Hearing Testimony to New York State Department of Environmental Conservation on the Proposed Brownfield Regulations Soil Clean Up Objectives

 

March 6, 2006

 

Presented by Ellen Z. Harrison, Director, Cornell Waste Management Institute, Cornell University.  EZH1@cornell.edu; 607 255-8576.

 

I am presenting these comments on the proposed Soil Clean-Up Objectives (SCOs) on behalf of myself and the other faculty members: Anthony Hay, Associate Professor of Soil Toxicology; Murray McBride, Professor of Soil Sciences; Brian Richards, Senior Research Associate; Tammo Steenhuis, Professor of Hydrology.  This same group provided comments to NYSDEC in June, 2004 on the fact sheets released by the department.

 

Please be advised that these comments represent our professional judgment and our work as Cornell faculty, but they do not represent the views of Cornell University.  No faculty can speak for Cornell.

 

More detailed written comments are also being submitted and are available at: http://cwmi.css.cornell.edu/brownfields.htm. These include:

·     The Implications of Proposed Clean-Up Standards on Water Quality by Brian Richards and Tammo Steenhuis.

·     What effect would including Vapor Intrusion have on the NYS DEC Proposed Brownfield Regulations Soil Clean-up Objectives (SCOs)? by Anthony Hay.

·     Comments on Metal Pollutant Standards in NYS DEC Proposed Brownfield Regulations Soil Clean Up Objectives by Murray McBride.

 

We appreciate the opportunity to comment and would be to discuss our submissions further.

 

We recognize that the development of these regulations is a challenging task that requires both a tremendous amount of technical knowledge and a balancing of science, policy and practicality.  We provide these comments in the hope that they will be useful to NYSDEC in developing the final rules.

 

Major points:

 

Proposed groundwater (GW) Soil Clean-up Objectives (SCOs) are reasonable in many situations and for many chemicals.  However they are not protective for some chemicals or situations such as: coarse, low pH soils; shallow GW; large contaminated areas relative to well recharge zones; preferential flow and facilitated transport; concentrated runoff thus high recharge; organic chemicals when travel time is rapid relative to degradation rate.

Example: Trichloroethylene concentrations in GW are predicted to be 47 times the drinking water standard under conditions of shallow, coarse soils.  Where runoff is concentrated and discharged so that recharge is accelerated, the exceedence is far greater.

 

The potential impact on surface water adjacent to a contaminated site needs to be addressed.  For some chemicals, this is a very sensitive pathway. Using copper as an example, the amount of watershed that could have soils at the GW SCO without causing a violation of DEC surface water criteria ranges from .3%-9% and only .003-.08% could have soils at the Industrial SCO without violating water quality standards.  (The range is due to different assumptions regarding hardness.)

 

The SCOs may be 10-100 times higher than concentrations that would protect people from exposure through vapor intrusion.

 

The cadmium soil background of 2.5 ppm used in the regulations is high and not consistent with data from other sources.  Using this value is not protective in unrestricted use garden scenario. The TSD method for estimating exposure to chemicals through the garden pathway is to multiply the ingestion by a factor of 5.  While this may be adequate for some chemicals, for others that are readily taken up by plants such as cadmium, this grossly underestimates potential exposure.

 

The proposed lead SCO for residential exposures is high. The more we learn about lead, it seems that any exposure represents additional risks.  Thus the lead SCOs particularly for residential uses should be as low as feasible, certainly below 400 ppm.

 

The proposed SCOs for Industrial and commercial use are not based on adequately protective assumptions.

 

The Industrial land use as proposed by DEC includes only exposure of an adolescent trespasser and a groundskeeper. There are potentially other exposures that need to be assessed. These include: site redevelopment and maintenance – repairs, laying pipes, new construction, etc. This would result in worker exposure. It would also generate dust and mud that could be relevant to neighbors and to other workers. Clothes may go home and expose people at home. Workers use the out-of-doors during lunch and other breaks. So ballfields, volleyball, picnic, etc. need to be assessed.

 

Vapor intrusion may be significant. Intrusion (infiltration) of contaminated groundwater into sewer lines, manholes that could impact workers in those spaces and potentially impact the wastewater treatment plant. Many industries have floor drains, these may be sources of vapors. May not have venting option if the building is on a slab.

 

Other potential exposures: Day care on site. Increasingly, businesses and industries are providing child day care.

 

The TSD value for adult worker soil ingestion in commercial and industrial Land Uses is 50 mg/day which is likely to be an average value.  EPA suggests (and TSD mentions) that 100 mg/day is appropriate for outdoor workers which is the worker scenario played out in the TSD. (see p 98-100 of TSD).  The soil ingestion calculations should be revised to reflect this higher ingestion rate.

 

Industrial LU assumes an outdoor worker spending 2 days/week in April-Nov outside.  TSD says if they spend more time, then use commercial SCOs.  How is this supposed to work from an implementation view? (p 92).  When a site is remediated, the plans may include outdoor work only 2 days/week, but if that were to change, it is unrealistic to imagine going back to further clean-up the site.  This argues for using, at a minimum, the commercial SCOs everywhere.

 

In the Commercial LU scenario it is assumed that and outdoor worker is exposed 4 days/week and seem to assume no exposure on day 5. How would outdoor work 5 days/week change the numbers?

 

Soil background

 

Soil background values for a number of inorganic elements used in the TSD are too high, likely due to analytic problems.  This is particularly important for cadmium where use of soil background may result in health concerns for gardeners.  The TSD method for estimating exposure to chemicals through the garden pathway is to multiply the ingestion by a factor of 5.  While this may be adequate for some chemicals, for others that are readily taken up by plants such as cadmium, this grossly underestimates potential exposure.

 

The use of the 98th percentile value rather than the 95th percentile is not justified.  For many chemicals the numbers are not very different, but for others use of the 98th percentile may result in excessively high values based on outliers.

 

Arsenic has both 16 ppm (proposed SCO for all uses except ecological) and 13 (ecological SCO) based on soil background.  This seems inconsistent.

 

Selenium is limited in the proposed ecological SCO to 3.9 ppm due to soil background but the unrestricted SCO is proposed to be 1 ppm.   This seems inconsistent.

 

Other issues

 

Farming if defined to include raising domestic livestock, is a reasonable scenario for residential use.  Raising chickens or animals for meat and milk poses risks not assessed in developing the SCOs.  Particularly for organic chemicals with a tendency to bioaccumulate in fats, this is a concern.  There is no effective way to preclude raising of animals by households.  Thus this needs to be assessed and addressed in the proposed SCOs.

 

The TSD assumes that inhalation exposure only takes place from April-Nov. (p 116).  This seems inappropriate since inhalation exposure would be year round.

 

Outdoor exposure assumptions for residential {in warm months kids (5 d/wk for 2 hrs) and adults (weekends only in garden)} seem low.  Gardening is a major hobby and some people are likely to garden for a couple of hours a day and many hours on weekends and some kids will spend the better part of every day outside. An analysis of the sensitivity of the proposed SCOs to this factor is needed. 

 

Enforcement

 

How will the need to address issues like requiring land records to reflect no day care, no recreational outdoor facilities at commercial and industrial sites, no gardens in restricted residential be enforced and no “farming” on any remediated sites be dealt with?  The regulations do not specify the mechanism.  Even if a mechanism is stipulated (such as notice on the land records), it is highly unlikely that there will be sufficient enforcement power to ensure compliance.  At least a requirement and language regarding putting notice on land records should be included in the regulations.

 

Parks.  The TSD mentions parks that are low public contact type as allowed in the commercial land use scenario.  Playgrounds are mentioned for restricted residential. The siting of playing fields is not mentioned in any LU category.  Where are they allowed? How will the restrictions on the kind of park use be enforced? Who will be the park police?

 

 

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