A study was carried out to determine the degree of biological activity in the drinking water supplied to New York City by the Croton and Catskill/Delaware systems, as measured by the Attached Growth Rate Estimate (AGRE) method. Also, possible relationships between AGRE results and standard water quality parameters were examined. The AGRE results for both the systems ranged between 0 and 0.5 d−1, indicative of biologically stable water. These results suggest that excessive bacterial growth in the New York City distribution system would be rare. The Croton results were temperature and alkalinity dependent. The Catskill/Delaware results revealed that growth rates decreased with travel time in the distribution system. These differences emphasize the complexity of biological activity monitoring in drinking water distribution systems.

This content is only available as a PDF.
You do not currently have access to this content.