Information
Groundwater from the Columbia South Shore Well Field is used as a secondary source for customers served by the Bull Run supply and also provides supplemental supply during the high-demand summer season. This page lists all the times we have used groundwater.
Common reasons we use groundwater:
- Maintenance operation: The groundwater supply is a complex system composed of pumps, chemical feed systems, electronic controls, and other appurtenances; it must be operated regularly to identify maintenance needs and issues. By doing this maintenance operation, the bureau will ensure the reliability of the system when needed, either in an emergency or as part of seasonal supply.
- Supply augmentation: During long, dry summers, the Water Bureau can blend groundwater with Bull Run water to make sure there’s enough for all during Portland’s dry season.
- Turbidity in Bull Run: If Bull Run water is unavailable for any other reason, such as a storm, flood, fire or natural disaster, groundwater can temporarily become Portland’s sole source of drinking water. Turbidity is a measure of the cloudiness of water caused by suspended particles. When turbidity is too high in the Bull Run, we cannot serve that water to our customers.
This table shows all instances that we used groundwater for drinking water and the reason we used it.
| Start date | Days used | Total volume pumped (billion gallons) | Range of daily production (million gallons per day) | Reason for use |
|---|---|---|---|---|
| August 24, 2023 | 83 | 3.2 | 18 to 78 | Supply Augmentation |
| November 22, 2022 | 2 | .03 | 5 to 30 | Augmentation due to Bull Run treatment equipment issue |
| November 5, 2022 | 17 | 1.3 | 50 to 85 | Turbidity in Bull Run supply |
| October 13, 2022 | 22 | 0.9 | 12 to 56 | Supply Augmentation |
| August 2, 2022 | 23 | 0.3 | 0 to 40 | Maintenance Operation (Groundwater was used approximately 10 hours/day M-F for the 23 day duration at an approximate rate of 40 MGD) |
| February 8, 2022 | 4 | .24 | 68 to 84 | In response to potential staffing shortages |
| November 15, 2021 | 3 | .14 | 26 to 76 | Activation due to storm damage to Bull Run Corrosion Treatment facility. |
| August 3, 2021 | 25 | 1.3 | 32 to 56 | Supply Augmentation |
| August 4, 2020 | 23 | 0.4 | 0 to 54 | Maintenance Operation (Groundwater was used approximately 10 hours/day M-F for the 23 day duration at an approximate rate of 54 MGD) |
| July 10, 2019 | 49 | 1.8 | 35 to 40 | Supply Augmentation |
| June 20, 2018 | 120 | 4.6 | 18 to 45 | Supply Augmentation |
| March 12, 2018 | 10 | 0.16 | 17 to 18 | Maintenance Operation |
| September 7, 2017 | 1 | 0.01 | 10.4 to 36 | Delay in material delivery |
| February 13, 2017 | 30 | 2.39 | 33 to 83 | Activation during Cryptosporidium detection investigation in Bull Run and annual maintenance operation |
| July 25, 2016 | 17 | 0.28 | 2.8 to 18.4 | Maintenance Operation |
| July 16, 2015 | 112 | 5.3 | 21 to 68.5 | Supply Augmentation |
| June 11, 2015 | 19 | 0.49 | 9 to 51 | Augmentation During Conduit Maintenance and Maintenance Operation |
| July 1, 2014 | 9 | 0.12 | 0 to 27.8 | Augmentation During Conduit Repair and Maintenance Operation |
| July 30, 2013 | 7 | 0.03 | 0 to 5 | Maintenance Operation |
| August 6, 2012 | 18 | 0.03 | 0 to 5 | Maintenance Operation |
| February 23, 2012 | 5 | 0.22 | 23.6 to 56.4 | Turbidity (Not a full Bull Run shutdown) |
| January 21, 2012 | 11 | 0.82 | 18 to 83.6 | Turbidity |
| August 9, 2011 | 6 | 0.03 | 0 to 22.3 | Maintenance Operation |
| January 16, 2011 | 17 | 1.3 | 8.5 to 88.7 | Turbidity in Bull Run supply |
| August 9, 2010 | 6 | 0.03 | 4.1 to 5.4 | Maintenance Operation |
| September 28, 2009 | 31 | 1.1 | 36 | Supply Augmentation |
| August 5, 2009 | 7 | 0.03 | 4 to 5 | Maintenance Operation |
| November 13, 2008 | 9 | 0.65 | 27.4 to 96 | Turbidity in Bull Run supply |
| August 18, 2008 | 6 | 0.003 | 4.7 to 6.4 | Maintenance Operation |
| September 28, 2007 | 13 | 0.43 | 18.3 to 36.4 | Supply augmentation |
| June 25, 2007 | 60 | 1.44 | 7.7 to 87.1 | Supply augmentation |
| November 7, 2006 | 14 | 1.1 | 27.8 to 92.2 | Turbidity in Bull Run supply |
| August 14, 2006 | 78 | 3.58 | 4.5 to 72 | Supply augmentation |
| July 27, 2004 | 29 | 1.01 | 36.5 | Supply augmentation |
| January 29, 2004 | 4 | 0.04 | 18.4 | Turbidity (Not a full Bull Run shutdown) |
| July 22, 2003 | 63 | 3.7 | 20.8 to 72.6 | Supply augmentation |
| October 8, 2001 | 12 | 0.44 | 6.9 to 45.8 | Supply augmentation |
| August 9, 2000 | 41 | 1.7 | 10 to 36 | Supply augmentation |
| November 25, 1999 | 19 | 1.5 | 19 to 89 | Flood and turbidity in Bull Run supply |
| December 28, 1998 | 5 | 0.35 | 29 to 93.6 | Turbidity (rain on snow event) |
| September 4, 1996 | 27 | 0.7 | 13 to 31 | Supply augmentation |
| February 7, 1996 | 8 | 0.5 | 4.9 to 86.6 | Flood and turbidity in Bull Run supply |
| November 28, 1995 | 27 | 0.7 | 5.1 to 29.8 | Landslide in Bull Run watershed (Damage to conduits, not a turbidity event) |
| August 2, 1994 | 73 | 2.5 | 2 to 36 | Supply augmentation |
| August 17, 1992 | 45 | 1.5 | 17 to 30 | Supply augmentation |
| August 7, 1990 | 23 | 0.22 | 4.7 to 14 | Supply augmentation |
| September 4, 1987 | 88 | 5.3 | 28 to 86 | Supply augmentation |
| February 25, 1986 | 22 | 1.2 | 21 to 84 | Turbidity in Bull Run supply |
| July 20, 1985 | 19 | 0.38 | 21 | Supply augmentation |