The broadly stated objectives of this project are to identify benefits and encourage usage of
aerobic spore monitoring as a tool to supplement other tools available to water plant operators
for evaluation and optimization of drinking water treatment. This includes evaluation of the
treatment facility as a whole (raw through filtration) as well as individual unit processes. One
particular application to be specifically addressed during this project is the use of spore
monitoring for the demonstration of performance (DOP) credit allowed in the LT2ESWTR. DOP
using aerobic spore monitoring is a potentially valuable and cost-effective tool (Cornwell et al.
2003) for regulatory compliance in the upcoming LT2ESWTR, particularly facilities needing
credits without extensive monitoring and capital improvement requirements. The DOP credit can
establish a 4 log or higher Cryptosporidium removal credit using existing facilities.
Existing historical data indicate that spore concentrations in the filtered water at drinking water
plants are frequently below the detection limit typically used (1 spore per 100 or 200 mL). Since
many U.S. source waters also have low raw water spore concentrations, a key issue to be
addressed in this project was to evaluate whether the current method can be refined by using
larger filtered water sample volumes, resulting in lower detection limits, or whether development
of an alternative sample collection and analysis protocol is needed to handle larger sample
volumes. Modifications that would result in lowering the detection limit would increase the
usefulness of spore monitoring.
This project investigated raw water concentrations in order to evaluate how low the filtered water
detection limits need to go in order to mathematically demonstrate a particular target spore log
removal (e.g., typically facilities may want to evaluate whether they meet the 4-log target for the
DOP credit). In addition, finished water data was investigated to see if spores are detected at
levels below the current 1 cfu/200-mL detection limit but above the detection limit needed to
demonstrate the target log removal. Includes 18 references, table, figure.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 300 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 10 |
| Published : | 11/02/2003 |
