In the course of its life, the mill manufactured and treated various wood products. These process included cutting logs into beams and planks, treating woods with tars and other chemicals to seal them, etc. By-products of these process were wood chips, saw dust, and particulates of the tar/creosote products used. After the plant was closed, its title passed to the County of Ashland and then to the City of Ashland, who eventually built a wastewater treatment plant on nearby land. For a period of time, a portion of this locale was used as a landfill by the City mostly for municipal waste and destruction debris. It opened sometime in the 1880s and closed in 1951. Built in 1951 and expanded in 1972, the wastewater treatment plant serviced the greater Ashland area. In the process of exploring further expansion options in 1989, contaminated soil and groundwater samples were found, indicating a potential problem. The City closed that plant, and built a new one a few miles away. Five years later, in 1994, an investigation was launched into the area to determine the reach of the contamination. The primary contaminants are tar (VOCs, SVOCs, heavy metals, oil sheens) and wood by-products (sawdust, chips, lumber, tar), as well as landfill waste. Additionally, some of the organic contaminants are concentrated into non-aqueous phase liquids (NAPL). Tar itself is a dangerous substance. In its makeup, it often contains polycyclic aromatic hydrocarbons and trace heavy metals, both of which are suspected to be carcinogenic. Additionally, the tar releases Volatile Organic Compounds (VOCs) and Semi Volatile Organic Compounds (SVOCs). VOCs and SVOCs contain carbon as a basis to their structure, and are prone to evaporating under normally reasonable temperatures and pressures. They are usually highly noxious, and can be harmful to the photochemical processes that are important to our atmosphere. The removal of these products is the main end goal for the remediation of the site, and is proving to be the greatest challenge to clean. Unlike tar, the wood is not inherently dangerous. It is the location and abundance of it that makes it a problem. Estimates say that the depth of wood by-products in the region of the bay ranges from two feet to ten feet thick, on top of approximately six feet of contaminated sediment. This makes the extraction of the contaminated sediment difficult and greatly increases the amount of material that has to be removed and cleaned.