West Otter is a city of approximately 50,000 population. The wastewater treatment facility is owned and operated by the city and it is located on the outskirts of town near Otter Creek. The wastewater treatment facility processes approximately 10 million gallons per day (mgd) of waste. This water is treated using gaseous chlorine in the process. The wastewater treatment facility has a chlorine storage facility for six one-ton cylinders of chlorine on site. Each cylinder, when full, contains approximately 1,700 pounds of chlorine. The water treatment facility utilizes approximately one cylinder per week, with two cylinders always connected in series to the waste stream. In the 45 years of operation at the plant, they have never experienced a release of chlorine that went off site.

However, two employees received minor injuries two years ago from chlorine inhalation while changing out a cylinder. There are at least two plant operators on site at all times at the plant. Within ½ mile of the city is one elementary school, two churches, and the municipal swimming pool. The plant has an active and ongoing training program for its employees.

worst-case and alternate scenarios require a plume projection to be developed showing the potential area impacted by a release. What are some possible reference sources (you) could use in determining the impacted areas and populations