Community Water Systems

The water systems that fall into this category have at least 15 service connections, or supply drinking water to 25 or more of the same people year-round in their residences. Neilson Research Corporation provides routine monitoring for cities, towns, subdivisions, and mobile home parks to meet these requirements. Our staff provides unquestionable data to satisfy regulatory authorities under the Safe Drinking Water Act.

Routine Chemical Monitoring

Community Water Systems are subject to the following requirements for the 2005-2007 compliance period.

This table describes base line monitoring only. You will find details on number, location and timing of samples at www.oregon.gov/DHS/ph/dwp.

Notes:

Inorganics

sampling (1993 and beyond) are completed and there are no Maximum Contaminant Level (MCL) violations.NitrateSynthetic and Volatile OrganicsDisinfection Byproducts DBP’sSynthetic OrganicsAsbestosRadionuclidesLead and Copper

: Testing frequency is once every 3 years following a minimum of 5 rounds of tap sampling. Initial sampling requirements are two consecutive six-month rounds. Both initial and reduced numbers of sample sites are based on population. Consult County or State program staff Department of Human Services Website for further details. : Four consecutive quarters of Gross Alpha, Combined Radium 226/228, and Uranium must be collected between 2004 and 2007 unless grandparented data is available. An initial sample set collected between 12/7/00 and 12/8/03 will substitute for the four consecutive quarterly samples.: Routine monitoring is one sample every 9 years if the system has asbestos-cement (A/C) pipe, or is located in an identified geographic area. Waivers may eliminate this testing. Monitoring will go to one sample every 3 years if the system exceeds Lead and/or Copper action levels.: Systems with population of greater than 3,300 must do two consecutive quarterly samples for Synthetic Organic chemicals during one year of the compliance period.: Initial sampling frequency for populations of 500 or greater (one set of samples/plant/quarter) Annual sampling frequency (one set/plant) during warmest month for populations of 25 – 499. Initial sampling frequency for populations greater than 10,000 is one set/plant/quarter.(DBP’s) Sampling reductions may be available based on results, population and source- consult program staff and/or web site for further details.: Testing for individual contaminates may be reduced to one sample every 6 years or 9 years, based on an approved Drinking Water Protection Program or a Use and Susceptibility Waiver.: Surface systems can reduce sampling to annually after 4 quarters. Quarterly sampling is required if there is a result between 5.5 and 10.49 mg/L. MCL violations require a confirmation sample within 24 hrs of notification.: Testing may be reduced to one sample every 9 years if three rounds of Phase 5 contaminant

Adopted from DHS website revised March 2006.