Fig. 3. Generalized alkalinity data (points) for cubitainer tests of the influent to Howe Bridge, Morrison, and Buck Mountain anoxic limestone drains (ALDs) and corresponding estimates of alkalinity concentration (C_t) computed on the basis of first-order (Eq. [7], dashed curves) and second-order (Eq. [10], solid curves) rate models and corresponding rate constants derived from cubitainer data (Fig. 4 and 5). (A) Howe Bridge and Morrison tests conducted under static–closed conditions (after Watzlaf and Hedin, 1993). (B) Buck Mountain tests conducted under static–closed and circulated–closed conditions.