Skip to Main Content View Text-Only

Portland Water Bureau

From forest to faucet, we deliver the best drinking water in the world.

GENERAL INFORMATION: 503-823-7404

1120 SW Fifth Ave, Suite 600, Portland, OR 97204

More Contact Info

Cryptosporidium Treatment Variance Monitoring Results

As required by the treatment variance for Cryptosporidium, the Portland Water Bureau has been monitoring for Cryptosporidium in the Bull Run since April 2012.

Below is a summary of these results from the source water intake. Detailed reports from the past 12 months can be found here.

Bull Run Intake Cryptosporidium monitoring results.

From April 2012 through December 2016, a total of 1,149 samples for a total of 26,159L (6,910 gallons) were tested with no detections for Cryptosporidium.

April   2012 through December 2016

Number of Samples

Positive Samples

Volume Sampled

1,149

0

26,159L (6,910 gals)

In January 2017 the first Cryptosporidium was detected at the Bull Run intake since December 2011.

2017 Results through March 15, 2017 (updated 3/20/2017)

Number of Samples

Positive Samples

Volume Sampled

Oocysts detected

52

14

2600L (676 gals)

19

 

Information on the positive samples from 2017 are below:

Date of positive   sample

Sample   Volume

No. of   Oocysts

Detected

Observation Monitoring

Jan. 2, 2017

50L (13 gals)

2

Jan.  3,   2017

50L (13 gals)

3

Demonstration Monitoring

Jan. 25, 2017

50L (13 gals)

1

Feb. 1 2017

50L (13 gals)

1

Feb. 7 2017

50L (13 gals)

1

Feb. 8 2017

50L (13 gals)

2

Feb. 13 2017

50L (13 gals)

1

Feb. 14 2017*

50L (13 gals)

1

Feb. 15 2017*

50L (13 gals)

1

Feb. 21 2017*

50L (13 gals)

2

 Feb. 22 2017*

 50L (13 gals)

1

 Feb. 26 2017*

 50L (13 gals)

1

 Mar. 8 2017*

 50L (13 gals)

1

 Mar. 12 2017*

50L (13 gals)

1

* Results do not represent water served to customers. From February 13 to March 15, Portland was using the Columbia South Shore Well Field as its drinking water source.

Observation Monitoring: Routine monitoring for Cryptosporidium at the Bull Run intake at least two days each week and each day when the turbidity is greater than 2.0 NTU.

Demonstration Monitoring: If Cryptosporidium is detected under observation monitoring, within one week the Portland Water Bureau must increase monitoring for Cryptosporidium to at least four days per week.