Manganese is a common mineral that naturally occurs in rocks and soil, and is commonly found in ground and surface waters in New England. It may also be present due to underground pollution sources. Manganese is an essential minieral for proper digestion, bone development and immune function. Primary sources in the diet include grains, beans, buts and teas. At excessively high levels, however, manganese can have adverse neurological effects. EPA has a secondary, aesthetic standard of 50 ppb. Above the 50 ppb level, consumers may notice a gray or lack coloring in their water and/or fixture staining. To be protective of public health MassDEP has a health guideline value of 300 ppb, and Consumer Confidence Report Notification Limit of 50 ppb. UMCR4 results for Wellesley are well below the state and EPA health and aesthetic standards.

Quinoline is a naturally occurring substance found in coal and is a component of coal tar and petroleum. It is used in the manufacture of dyes, pharmaceuticals and some personal care products, and is present in some foods and beverages. Quinoline is present in tobacco smoke, which is a significant source of exposure for people who smoke and people exposed to secondhand smoke. Given the uncertainty in health effects, EPA provides a wide range for its health reference level (HRL), from 0.01 to 1 ppb. Minnesota has published a non-regulatory guidance value of 0.03 ppb. The average quinoline levels in Wellesley are low based on the HRL.

Ortho-Toluidine is a chemical used in the manufacture of dyes, some pharmaceuticals and pesticides. It is also used to make rubber materials. Exposures to high levels of this chemical are usually in a workplace setting. o-Toluidine can also be found in tobacco smoke. It has been found at low levels in a variety of foods including fresh kale. celery, carrots, peas, red cabbage, and black tea. It is slightly soluable in water. In workplace settings where chronic exposure may occur, this chemical may cause effects on the spleen, liver, blood and bladder. This chemical is most toxic when absorbed through the skin. o-Toluidine has been found in surface waters and industrial wastewater.