Drinking Water Program

The State DHS Drinking Water Program contracts with Environmental Health to administer and enforce drinking water quality standards for public water systems in Clackamas County that use groundwater and serve a population of 3300 or less. Clackamas County has over 200 public water systems that meet these criteria. A sanitary survey is conducted at these systems once every three to five years.

Clackamas County's Drinking Water Program is a resource for water system operators and the public when dealing with water quality alerts, public notices, water monitoring & testing, and sanitary hazard analysis. We do not regulate or inspect private wells. We do inspect the following water systems:

• Community Water System: A water system which supplies drinking water to 25 or more of the same people year-round in their residences. Examples are cities, towns, subdivisions, mobile home parks, and the like.
• Non-transient Non-community Water System: A water system which supplies water to 25 or more of the same people at least six months per year in places other than their residences. Examples include schools, hospitals and work places.
• Transient Non-community Water System: A water system which provides water in a place such as a restaurant or campground where people do not remain for long periods of time.
• State Regulated Water System: Water systems which provide water to small residential communities between 4 and 14 connections, or serves from 10 to 24 persons a day at least 60 days a year, or is licensed by the Health Division or delegate county health department but is not a Transient Water System

For more information about clean drinking water, including monitoring information and operator certification, visit the state of Oregon’s Drinking Water program at http://public.health.oregon.gov/PHD/OEPH/DWP/Pages/index.aspx

Private Wells and Water Systems
While we do not test private wells or water systems, it’s important for all of us to have clean drinking water. Oregon State University has some excellent information for homeowners and others who use private wells or other private water systems. Go to http://wellwater.oregonstate.edu/ The Environmental Protection Agency also maintains an informative website on safe drinking water http://www.epa.gov/safewater/privatewells/index2.html

Real Estate Transaction Water Test
When you buy or sell real estate that includes a domestic well, the lender or buyer may require a well test. Our Environmental Health Inspectors can assist you if your water system meets the following conditions:

1. Water system must be in operation.
2. Source of water (well head or spring box) must be completely sealed and the air vent screened to prevent possible contamination. Wells without sanitary seals or undeveloped springs or surface supplies will not be tested.
3. Source of water system (well head or spring box) must be accessible for construction review.
4. All residual chlorine from disinfecting water source must be flushed out.

Note: If you need your septic system reviewed contact Clackamas County Water Environment Services at 503-742-4567 or go to their website: www.clackamas.us/wes/faq.jsp

For a water system inspection, you must fill out an application and pay the required fees:

Fees Schedule (Make check payable to: Clackamas County Community Health Division)

In addition to your application, you will need to provide:

1. The legal description (map number) of the property.
2. An adequate diagram must be drawn on the application showing the location of the water and sewage disposal systems serving the property.
3. Adequate driving instructions to the property.

Inspections are done on Monday. Applications must be received and accompanied by the required fee and other paperwork, at our office by Thursday at 4:00 p.m. Once the inspector completes the report, a copy of the report will be mailed to applicant. Any additional copies are available for $1.00 per copy.

Disinfecting Wells. If you have any work done on your well, you may need to disinfect it. Construction or maintenance work, such replacing the pump in an existing well, can temporarily contaminate well water with coliform bacteria. Bacteria from soil, vegetation, and the tools and hands of the maintenance crew could enter the well. Before using the water, disinfect and flush the entire system and then sample for coliform.

The procedure is as follows:

For each 100 gallons of well water, add two cups (16 ounces) of household bleach (5% sodium hypochlorite) available from grocery stores.

EXAMPLE: How much 5% bleach is needed to disinfect a well with a 6 inch diameter casing and now has 65 feet of water? Answer: The table below shows there are 1.5 gallons of water for each foot of water depth for a 6" diameter well. Multiply the total water depth of 65 feet X 1.50 gallons per foot = 97.5 gallons of water in this 6" diameter well. Since 97.5 feet is about 100 gallons, add 2 cups of 5% bleach to the well to disinfect it.

Calculate the gallons of water in the well by using the following table:

1. Add the bleach to 4-5 gallons of water and pour in the well. Use a plug or casing vent hole in the top of the sanitary seal.
2. Be sure the bleach mixes thoroughly with the well water. Attach a hose from pump or service line and run water into the well. Use the same hole in the top of the sanitary seal used to add the bleach.
3. After 15 or 20 minutes, open each fixture served by the well until you can detect a bleach smell in the water then close the valves. Let the bleach stand in the well and plumbing for adequate contact time, at least 8 hours.
4. Thoroughly flush the system.
5. Sample for total coliform. A good sample location is a bathroom faucet with the aerator removed. Wait until lab reaults are negative for total coliform before using the water.

It is difficult to flush an entire system when it is large. The well should be isolated, disinfected, flushed and sampled for total coliform. If total coliform samples are positive, repeat the disinfection process until samples are negative. The repeat procedure must be followed in sequence: disinfect, flush all bleach, and wait for sample results before resuming service. Schedule maintenance in advance so there is adequate time to disinfect and be sure water is safe for use.

Warning: Be sure bleach used in this process is flushed thoroughly from all service lines. Remember that bleach contains chlorine which is harmful to aquarium fish.