Padilla Bay tributaries bacteria TMDL

Padilla Bay and its freshwater tributaries have high levels of fecal coliform bacteria. For this reason, the four major sloughs that drain into Padilla Bay are listed on the Washington state list of impaired water bodies, known as the 303(d) list. The bay also serves as a popular destination for school groups and recreational activities. To preserve the use and enjoyment of these waters, we're working to make the water safe and healthy again. We've developed a Padilla Bay Water Quality Improvement Report known as a Total Maximum Daily Load, or TMDL. This report and implementation plan determine the best method to bring Padilla Bay back into compliance with state water quality standards.

Our final plan

We have submitted the Padilla Bay Freshwater Tributaries Bacteria Total Maximum Daily Load (TMDL) water quality improvement plan. This water quality improvement plan aims to address high bacteria levels in the freshwater portions of the Padilla Bay watershed. The goal of this water quality improvement plan is to identify water quality and riparian habitat improvements needed to support freshwater recreational uses in the Padilla Bay watershed. We held a comment period from Oct. 22, 2020 to Nov. 22, 2020. We also hosted two online public workshops about the draft TMDL on Oct. 28, 2020. The comments and our response to comments are included as an Appendix to the plan. We submitted the final TMDL to EPA for approval on Dec. 15, 2020. EPA approved the TMDL on Dec. 22, 2020. Once finalized and implemented, this plan should ensure safe conditions for swimming and other recreational activities. You can view comments online in eComments

Water quality issues

The Padilla Bay watershed is located in Northwest Skagit County. It consists of four major sloughs and many interweaving drainage systems. In all four of these sloughs, fecal coliform bacteria numbers exceed the maximum allowed under state water quality standards.  Currently, Padilla Bay and the freshwater tributaries do not meet the state standards for wading and swimming.

There are multiple potential sources of bacteria that lead to dirty water in the Padilla Bay watershed, such as:

  • Rural, residential, commercial, industrial, and urban stormwater runoff.
  • Wildlife feeding and habitat areas.
  • Livestock on commercial and non-commercial farms.
  • On-site septic systems and illicit sanitary connections.

What we've done

We conducted several field surveys in the four freshwater sloughs that drain into Padilla Bay from 2016 to 2018. We used the data collected during these surveys to develop reach-specific bacteria loading capacities for each tributary, and estimated load reductions necessary to meet these capacities.

We started developing the Padilla Bay Freshwater Tributaries Fecal Coliform Bacteria TMDL plan in 2015. To start the process, we held a public meeting on Oct. 1, 2015. We will hold several Technical Advisory Work Group meetings from September to November 2020. We submitted the final report to the Environmental Protection Agency (EPA) for approval on Dec. 15, 2020.

Why this matters 

High levels of bacteria pollution in streams and lakes are a risk for disease to humans and animals that are exposed to contaminated water. The state is required to protect the “most sensitive” beneficial uses found in water bodies, which include the ability to wade, swim, and fish in lakes, rivers, and streams. This watershed cleanup plan will specifically reduce bacteria pollution within the No Name, Big Indian, Little Indian, and Joe Leary Sloughs that drain into Padilla Bay.

How can you help?

We're working with a wide range of partners to address the bacteria contamination problem in the Padilla Bay watershed. Everyone can be a part of improving water quality conditions. Some key actions that groups and individuals can take to help reduce bacteria include:

  • Pick up your pet waste
  • Have septic systems inspected regularly to avoid pollution and costly repairs
  • Improve stormwater management practices
  • Modify livestock management practices to reduce animal contact with surface water
  • Protect existing streamside vegetation, and plant new vegetation where possible to help filter contaminated runoff
  • Adopt agricultural practices that conserve water and soil

Here are some contacts and resources to get you started:

  • Skagit Conservation District: (360) 428-4313
  • Skagit County Health Department: (360) 416-1500
  • Skagit County Natural Resources Division: Michael See -