Suppose an underground storage tank has been leaking for many years, contaminating the groundwater and causing a contaminant concentration directly beneath the site of 0.30 mg/L. The contamination is flowing

at the rate of 1.5 ft per day toward a public drinking water well 2 mile away. The half-life of the contaminant is 10 years. If the PF for the contaminant is 0.02 (mg/kg-day), estimate the cancer risk if a 70-kg person drank 2 L of this water per day for 10years. If the cancer risk is equal to X in 1 million population, find the X.