|
|
| Introduction :: Data Search Options :: Water System Search :: DWS Home :: DWS Rules |
OHA Drinking Water Services
Contact Report Details |
|||
| PWS ID: | OR41 00262 | ||
| PWS Name: | DUNDEE, CITY OF | ||
| Who Was Contacted and Phone: | Gary VanDerVeen (503) 434-7439 | ||
| Contact Date: | 02/17/2016 | ||
| Contacted By: | HOFELD, EVAN (REGION 1) | ||
| Contact Method/Location: | Office | ||
| Assistance Type: | WATER QUALITY ALERT RESPONSE | ||
| Reasons: | GWR GWR |
||
| Details: | SUMMARY: 4-LOG Treatment Confirmed DETAILS: System had a confirmed e-coli in sampling completed July 2011 for the spring well #2 (SRC-AB). The well was subsequently taken off-line. Water Resources Dept established that both spring well #1 and #2 are hydraulically connected. Results of the Source Water Assessment indicated that well reconstruction was not likely to eliminate the E.coli or viral contamination. On 5/5/15, City submitted the final revised Disinfection Verification Form demonstrating 4-log disinfection at 400 gpm with 27.5 minutes of contact time at a minimum free chlorine residual of 0.2 mg/l (400 gpm is the firm pumping capacity with 2 of 3 pumps in service). City started GWR Compliance Monitoring 4/1/12. A Final Approval letter dated 1/5/16 for the new well #11/13 (SRC-AE - L77100) reaffirmed 0.2 mg/l minimum residual for flows up to 400 gpm and indicated a higher residual would be needed for higher flows (e.g. up to 0.3 mg/l for up to 700 gpm, the capacity of the new pipeline extending from the sources to the clearwell/pump station). ACTION NEEDED: City to continue daily compliance monitoring demonstrating that they meet a minimum entry point chlorine residual of 0.2 mg/l for 4-log viral disinfection at entry point A (EP-A) for flows up to a maximum of 400-gpm (400 gpm is the firm pumping capacity with 2 of 3 pumps in service). | ||
| Associated Alerts: | COLI9505 - 08/15/2011 - COLIFORM (TCR) , E. COLI COLI9505 - 08/15/2011 - COLIFORM (TCR) , E. COLI COLI9505 - 08/15/2011 - COLIFORM (TCR) , E. COLI COLI9505 - 08/15/2011 - COLIFORM (TCR) , E. COLI COLI9505 - 08/15/2011 - COLIFORM (TCR) , E. COLI |
||