unit used throughout the PTM) at some specific location on the river, can be calculated as follows:

(1.1)

where2

L = (preremedial) metal loading in the Coeur d’Alene River at the specific location examined (pounds/day);

Zref = “loading potential” per unit volume (pounds/day/cubic yard) for the reference source type for the location on the river under examination (averaged over all sources of that type affecting that location);3

RLPj = “relative loading potential” for the location on the river under examination for a contamination source of type j, averaged over the sources of that type that affect the river location under examination (for the reference source type, the RLP is unity);

Vij = volume (cubic yards) of a source of type j with index i that affects the river at the location examined, all such sources being indexed;

K = number of different types of sources that affect the river at the location examined; and

Nj = number of sources of type j that affect the river at the location examined.

The contamination sources are generally volumes of contaminated soil, sediment, and rock, categorized by type. The source types used in the PTM (pp. 2-18 to 2-19), for the upper basin, conceptual site model (CSM) Units 1 and 2, are adits (these are treated specially, by using measured flows and concentrations and deriving an effective volume for them), tailings-impacted floodplain sediments, unimpounded tailings piles, impounded tailings piles at inactive facilities, impounded tailings piles at active facilities, waste rock piles in floodplains, waste rock piles in upland areas, and deeper impacted floodplain sediments (unremediated sources).

The reference source type (with RLP = 1) is taken to be tailings-affected floodplain sediments.

2  

The notation of the PTM is adopted, except that all symbols are italicized to agree to the degree possible with standard notational conventions (which are not observed in the PTM). The only possible confusion is between the symbols L and L which have distinct meanings in the PTM; however I avoid this confusion by using a different symbol, W, for what the PTM calls L.

3  

Only ratios of quantities each of which multiplies what I here call Zref are required in the PTM, so no such term is defined anywhere in the PTM. The exposition is made more concise and direct by introducing Zref explicitly.



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