Paintshop Pond:
We Want You to Know

June 1999

This is one in a series of information sheets, prepared by Wellesley College, on the cleanup of the former Henry Wood's Sons paint factory, located on the Wellesley College campus. This update provides you with information on the Phase II Comprehensive Site Investigation and results of the Human Health Risk Assessment. This information was used to guide our evaluation of cleanup options.


(Click to view the May 1998 Information Sheet)

(Click to view the April 1999 Information Sheet)

In This Edition

Extent of Contamination

Who Might Be Exposed

What We Found

A Human Health Risk Assessment of the Former Henry Wood's Sons Paint Factory Site at Wellesley College

We recently updated you on our evaluation of alternatives for cleaning up the former Henry Wood's Sons paint factory site on the Wellesley College campus. This update summarizes the results of the Comprehensive Site Investigation undertaken by the College to determine the nature and extent of contamination resulting from the factory's operations. Using this information - derived from the extensive testing of soils, sediments, groundwater and surface water in the site area - the College conducted a Comprehensive Human Health Risk Assessment. A Risk Assessment evaluates the potential risks to human health, public safety and welfare, and the environment, as a result of exposure to contaminants. This fact sheet addresses the potential risks to human health. Our next update will address potential risks to the environment.

Our efforts to monitor, test and clean up contamination on the campus are subject to the Massachusetts Contingency Plan (MCP), which is administered by the Department of Environmental Protection (DEP) and calls for the investigation and cleanup of contaminated sites.

In all, more than 6,000 tests have now been undertaken to determine the type and extent of contamination resulting from the former paint factory's operations.

From 1848 until 1910, the Henry Wood's Sons paint factory was one of the largest manufacturers of paint pigment in New England, located west of the campus and south of Route 135. Historic evidence suggests that the factory had a separate building on the property for producing green, red and yellow colors, and a lead smelter that was used for producing various shades of white and yellow. The production of colored paint pigment involved the use of many chemicals, including:

From the production of pigments, wastes that contained metals were discharged into the soil and nearby bodies of water.

Extent of Contamination

Our site investigation results show the presence of metals and cyanide in soils at different concentrations throughout the site. Concentrations of these substances are measured in milligrams of metal per kilogram of soil. [A kilogram weighs 2.2 pounds, or 35.2 ounces. A milligram is 1/1000 of a kilogram and weighs .0352 of an ounce]. Of all the metals present in the soils and water bodies, only those that were believed to be used in the pigment manufacturing process, or whose concentrations are above that which is naturally occurring, are carried through the risk assessment. These are called the compounds of concern. These include lead, chromium, arsenic, zinc, silver, barium, aluminum, copper, cadmium, nickel, and selenium. The compounds that were present on site, in the highest concentrations and with the highest frequency, are lead and chromium. In the uplands area, paint pigment is evident just beneath the ground surface, and at depths between six and ten feet, in about 60% of the area.

Range in the Uplands

Lead: 1 mg/kg-214,000 mg/kg
Chromium: 2 mg/kg-110,000 mg/kg

Range in the Wetlands

Elevated concentrations of lead and chromium are also present in the soils of the wetlands located to the east and southeast of the former paint factory.
Lead: 2 mg/kg-150,000 mg/kg
Chromium 8 mg/kg-110,000 mg/kg

Range in Groundwater

Concentrations of metals in groundwater are measured in milligrams (mg) per liter (l) of groundwater. [A liter is 33.6 ounces].
Lead: 0.002 mg/l - 0.39 mg/l
Chromium: 0.0027 mg/l - 9 mg/l

Range in Paintshop Pond Sediments

Lead: 34 mg/kg-14,700 mg/kg
Chromium: 41 mg/kg-6,290 mg/kg

Range in Lake Waban Sediments

Lead: 0.72 mg/kg-94,000 mg/kg
Chromium: 3 mg/kg-17,000 mg/kg

Any assessment of risk must answer two questions: (1) whether contamination exists at a level associated with some adverse effect, and (2) the likelihood that someone might come into contact with or be exposed to the contamination. The DEP allows for several different approaches to performing a risk assessment. The most comprehensive is referred to as "Method 3". This type of assessment uses site-specific information - including levels of contamination and exposure.

Protecting the Public

During the past five years, the College has taken a number of steps to reduce the possibility of exposure to contamination:

Human Health Risk Assessment

The purpose of the Human Health Risk Assessment is to evaluate the potential for risks, based on current site conditions (with the fence surrounding the former factory location), and potential future site conditions (if the fences were removed and the area were open to recreation in the absence of any cleanup). To evaluate risk requires looking at the levels and type of contamination that exist and determining the likelihood that someone might come into contact with, or be exposed to, contamination. The results of the site investigation determined the concentrations of metals and cyanide in soil, sediment, surface water, and groundwater and fish tissue. The risk assessment considers possible exposures to the compounds of concern. The metals detected most frequently and in the highest concentration are lead, chromium and arsenic. Next, we developed with DEP a number of possible exposure scenarios (approved by DEP) that considered who might be exposed to contamination. We made assumptions about the types of behavior children and adults might engage in that would result in exposure, and how often adults and children might be exposed.

Risks to individuals who might be engaged in variety of activities were evaluated. Descriptions of these activities were made by the College and DEP, in order to determine how people might be exposed to contamination at the site. Risks were determined for people who would be most sensitive to the adverse effects of lead, chromium, cyanide and arsenic. Pregnant women and children under age six are most sensitive to the effects resulting from exposure to site contaminants. Other individuals will likely have risks that are lower than, or equal to, those predicted for sensitive individuals.

Who Might Be Exposed (and How Often) to Site Contaminants

The College and DEP agreed that the following exposures should be evaluated:

Current Conditions

Future Conditions

Pathways of exposure to metals and cyanide in soils, sediments, surface water and fish for these individuals were considered, and include:

What We Found

Based on the assumptions used in this assessment, risks were identified for those individuals who ingested lead, arsenic or cyanide in soil or sediments, or who had skin contact with chromium contaminated soils. Most of the estimated risk is due to the ingestion of lead in sediments and soils.

Under current conditions, risks were identified for: Trespassers who go inside the fenced area Young children (less than six years old) who swim or wade in the northern shoreline or western cove of Lake Waban Arsenic, cyanide and chromium can have health effects associated with a single exposure. We have actual measurements of arsenic and cyanide at the site. The levels of chromium for most of the site are conservative estimates (i.e. the estimated concentration is higher than the actual concentration is likely to be). The risk assessment looked at risks associated with a one-time ingestion of cyanide and arsenic in soils, and one-time direct skin contact with chromium contaminated soils. These are called acute health risks. Acute health risks are identified, following a single exposure to soils located: Inside the fenced area (due to arsenic, cyanide and chromium) In a limited area adjacent to the paved portion of the walking path (due to chromium) In the field hockey and soccer fields on the campus (due to one sample, in each field, in which the concentration of chromium was estimated) Under future conditions, risks were identified for: Adults and children who might be engaged in recreational activity (if the fence were taken down and no cleanup occurs)

Risks were not identified under current or future site conditions, for:

Groundwater Risks

At the present time, no one is using the groundwater at the site for a drinking water source. However, the groundwater on the site has concentrations of lead and chromium that exceed Massachusetts drinking water standards. The College's drinking water supply wells and the Town of Wellesley's water supply are not affected by the contamination. The College continues to monitor the groundwater that flows toward the drinking water supply wells for the presence of contamination.

People should avoid contact with, or activities in, areas where contamination is known to exist

Imminent Hazard Evaluation

A sampling of sediments in Lake Waban showed the presence of high levels of lead, arsenic and chromium in the northern shoreline and the western cove. The College performed an "Imminent Hazard Evaluation" last year to determine whether conditions in these portions of the Lake pose - on a short-term basis - a significant risk to health. This evaluation assumed a young child or adult would be exposed three days per week in warm weather (36 times over the course of the summer), and that exposure to metals in Lake sediments was due to skin contact with the water, and from children swallowing a small amount of sediment each time a child waded in the water. Lead in sediments at the northern shoreline poses a potential hazard for children - under the age of six - who swim or play at a distance of 15 to 50 feet off the northern shoreline. There was no imminent hazard to children or adults who swim or wade in the western cove of the Lake.

What are the health effects of lead?

Lead is a metal that can have adverse health effects, depending on the amount that gets into your body. Lead is particularly harmful to the developing brain and nervous system of young children and fetuses (Center for Disease Control, 1991). Children and adults are exposed to lead from many sources including air, food, and drinking water. Exposure to lead, regardless of the source, can be detected in the blood. Research has shown that adverse effects of lead on the developing nervous system occur at blood lead levels as low as 10 ug/dL. Blood lead levels as low as the target level, and slightly above, do not cause distinctive symptoms, but are associated with a decrease in intelligence, decreased stature or growth, and decreased hearing ability. Children with a consistent blood lead of 15-19 ug/dL can suffer adverse effects such as mild to moderate decrease in IQ, shortened attention span, and learning and behavioral difficulties. Children with blood lead levels between 20-69 ug/dL are considered Lead Poisoned. These children, depending on their age, lead level, and duration of exposure, may exhibit some visible effects of lead poisoning such as speech delays, hyperactivity, regression of recently acquired skills, irritability and change in appetite (Massachusetts Department of Public Health). Depending on the blood lead levels,various medical treatments are available. Most childhood lead exposures result from inhaling lead paint dust, eating lead paint chips, and drinking water containing lead. In Massachusetts, the Department of Public Health requires that all children, regardless of whether they are known to be exposed to any particular source of lead, be tested for lead exposure at least once between the ages of nine and twelve months, and annually thereafter until they are five years old. Regardless of the results of this Risk Assessment, if you are concerned about your child's exposure to lead, their blood lead level should be measured. You may already have this information from the yearly screening. While the blood lead test does not give information on the source of lead exposure, it will tell you whether or not any medical attention is needed. We recommend that if you have any concern about lead exposures to your children, you contact your pediatrician and request a blood lead evaluation. The U.S. Centers for Disease Control recommends a target blood lead level of 10 ug/dL for children under the age of 6 to protect children from the adverse effects of lead.

The risk assessment was conducted in such a way that risks would most likely not be underestimated. It is important to remember that the risk assessment looks at the likelihood of adverse effects on human health. It cannot determine whether any actual risks have occurred. The risk assessment also assumes that no cleanup occurs. The results are used to help decide whether the contamination that is present needs to be addressed - so that the possibility for exposure and harm will no longer exist.

This is one in a series of information sheets designed to answer some of the questions that you and your neighbors may have about the cleanup process. We recognize that keeping an open dialogue with you is an essential part of our commitment to safeguarding human health, the environment and community well-being.



(Click to view the May 1998 Information Sheet)

(Click to view the April 1999 Information Sheet)

Mary Ann Hill
Director of Public Information and Government Relations
Wellesley College
(781) 283-2788

Steven Johnson
Project Manager
Massachusetts Department of Environmental Protection
205A Lowell Street
Wilmington, MA 01887
(978) 661-7710

Office for Public Information
Last Modified: January 11, 2001