Prepared a Position Brief that provides estimates of the potential contribution of contaminants of concern (COCs) to river sediment from a former manufacturing site. Calculations considered evaluation of historical data to estimate COC mass flux due to sewerage discharges. Evaluation shows that client’s potential contribution is de minimis. Also identified mathematical error in Cost Allocator’s protocol.

The focus was on estimating the mass flux of metals (copper, mercury, and lead) due to permitted sewer discharges and evaluating whether the client’s contribution warranted financial responsibility under the allocation process. A thorough site assessment and characterization confirmed that the only potential pathway for client-related COCs to reach the river was via permitted discharges. The allocation assessment followed the prescribed allocation protocol, applying conservative “worst-case” assumptions to estimate the potential COC contribution. The evaluation demonstrated that even under highly conservative assumptions, the client’s allocation base score was negligible.