This paper summarizes the results of a water quality master plan that was completed for Erie City Water
Authority's (ECWA) Chestnut Street and Sommerheim water treatment plants. Specific issues that were
addressed included disinfection, liquid stream processes, and residual disposal alternatives. Specifically,
this paper discusses the disinfection alternatives, including ultraviolet (UV) light, that were considered for each
treatment plant and the final alternatives that were selected for each plant to comply with the
Pennsylvania Department of Environmental Protection (PADEP) disinfection design requirements.
Both plants currently produce high quality water and meet all of the major drinking water regulations (i.e.
D/DBP's, ICR, IESWTR, etc.); however, due to the limited clear well volumes with little or no baffling, both
plants cannot meet the PADEP disinfection design requirements. Currently PADEP requires that new or
modified water treatment plants be designed to achieve 3-log inactivation of Giardia through the
treatment plant with at least 1-log inactivation of Giardia occurring after filtration. Both treatment plants
are currently "grandfathered" under this regulation, which means they are not required to meet the
disinfection requirements outlined above. However, due to the age of both treatment plants, ECWA is
planning on upgrading their liquid as well as solids stream processes. With these modifications, the plant
will no longer be grandfathered under the regulations; therefore, they will need to consider disinfection
alternatives which will allow them to comply with the PADEP standards as well as the anticipated
inactivation requirements for Cryptosporidium in the LT2ESWTR which may also be adopted by PADEP.
Based on the process and site conditions, it was determined that UV light followed by chlorine is the best
option to meet the LTESWTR and the PADEP disinfection requirements.
Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 770 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 20 |
| Published : | 06/16/2002 |
