Skip to main content
Oregon.gov Homepage

New Beach Action Value

Changes for the 2017 beach monitoring season

The Oregon Beach Monitoring Program (OBMP) has adopted a new beach action value (BAV) for bacteria of 130 MPN that will be used as the basis for public health advisories for the 2017 monitoring season.

The adoption of the new BAV is recommended by EPA in the pdf2014 National Beach Guidance and Required Performance Criteria for Grants. Studies suggest that exposure to bacteria levels below 158 MPN may still cause gastrointestinal illnesses from accidental ingestion of water during recreational activities. Please read the information below for additional details. 

What is a BAV?

BAV stands for beach action value. The BAV is the marine recreational water quality standard used to determine if bacteria levels are unsafe for water contact. When a single marine water sample has bacteria levels at or above the BAV, a health advisory is issued. Once a health advisory is issued, people are asked to avoid water contact until the health advisory is lifted. 

Since the establishment of OBMP in 2004, the program has used 158 MPN (most probable number) as the BAV. Starting for the 2017 sampling season, OBMP will use 130 MPN as the BAV.

Why is the new BAV so much lower? 

In 2014, the Environmental Protection Agency (EPA) updated its pdf National Beach Guidance and Required Performance Criteria for Grants (Beach Guidance). Studies conducted by the EPA found that recreating (playing, swimming surfing, etc.) in water with bacteria levels below the current BAV of 158 MPN pose a health risk. The updated guidance provides safer standards for recreational waters across the U.S. and will help focus resources on the highest priority beaches. A part of EPA’s guidance, requires states who receive funding for beach monitoring to adopt a BAV no greater than 130 MPN.

Additional information about the studies can be found in the EPA’s Beach Guidance.

What does MPN mean?

MPN stands for most probable number. MPN is a testing method used to estimate the number of colony forming units (of bacteria) in 100mL sample of water. When water samples indicate the number of colony forming units has reached the BAV (130 MPN) a health advisory is issued for the beach that the water sample was collected from.

Why is OBMP adopting a new BAV?  

People are primarily exposed to bacteria in water by accidental ingestion (swallowing water). Because EPA studies have shown that lowering the BAV to 130 MPN can help reduce the number of people who become ill when exposed to bacteria contaminated water, OBMP believes that adopting this new BAV will better protect the health of Oregonian’s, and those who visit our state beaches.  

EPA developed a pdf fact sheet that summarizes changes in the Beach Guidance.

Why is OBMP waiting until 2017 to use the new BAV when the guidance was updated in 2014?

Once a standard is in place it takes time to determine and plan for the resources and procedures required to ensure the program runs efficiently and that the work performed is effectively protecting people’s health. 

As part of the planning process, OBMP is required to ensure that the public is informed of the changes being made to the program, and the effects these changes will have on the work of the OBMP.

How is OBMP informing the public about the BAV changes?

The OBMP and the Oregon Department of Environmental Quality (DEQ) hosted four public meetings in the fall of 2015 along the coast and in Portland. The purpose of the meetings were to provide information, solicit public feedback, and to answer your questions. 

A copy of the slides presented at the meetings are available here - pptOMBP Presentation.

Will the new BAV effect the number of beaches sampled or the sampling schedule?

OBMP monitors beaches on three week rotating schedule depending upon their geographic location, previous monitoring data and test results, public input and amount of beach use (available on the gif Beaches We Monitor webpage). However, when an exceedance of the BAV is discovered and an advisory issued, OBMP collects a resample within 96 hours to determine if bacteria levels have decreased enough to lift the advisory. 

With the lower BAV the OBMP expects to see an increase in the summer sampling workload and the number of advisories issued. This expected increase could affect the number of beaches monitored as well as the 96 hour turnaround for beach re-samples. Beaches that can be effectively monitored will be determined before the start of the 2017 season and as resources permit, OBMP will continue to use its current sampling schedule. However, if the workload increases to a level where OBMP can no longer effectively sample or re-sample a beach according to our schedule, modifications will need to be made.

Will health advisories increase? 

Looking at past data, it’s possible that the number of health advisories may increase. Many factors, including rainfall can impact the number of health advisories issued. Although OBMP believes there will be an increase in the number of health advisories based on the new BAV, it’s uncertain how much the number will increase until sampling begins for the 2017 season. 

If there are more health advisories, does that mean the water quality is worse than before? 

Not necessarily. Since the BAV is being reduced by 20% (from 158 MPN to 130 MPN), the change is expected to increase the number of health advisories issued, even if water quality remains unchanged. An increase in health advisories is not expected to occur because water quality is worse than before, but that advisories will be triggered more often by the lowering of the BAV. 

OBMP will continue to compare new sampling data to historical monitoring data collected from Oregon beaches since 2004. Any water quality changes identified are communicated to partners and local jurisdictions for further action.

Will the BAV and the marine recreational water quality standard (WQS) still be the same?

The BAV and the marine water quality standard (marine WQS) will no longer be the same. The BAV will go from 158 MPN down to 130 MPN, while the marine WQS to be adopted by Oregon Department of Environmental Quality (DEQ) will be the same as the value found in the 2004 EPA beach Guidance document.  While OBMP is adopting a new BAV, DEQ is going through a parallel process to adopt a new recreational marine WQS in Oregon. The OBMP will use the new BAV to trigger health advisories as necessary when bacteria exceedances are found, while DEQ will use the new marine WQS for permitting purposes, and to assess the quality of water in a particular water body or watershed. 

Information about EPA’s recommended changes to the recreational marine water quality standard is included in the  Beach Guidance and the  2012 Recreational Water Quality Criteria.

How can I find more information about DEQ's water quality standard rulemaking process?

Please visit DEQ’s  Water Quality Standards Revisions for Bacteria webpage for more information.For questions about DEQ's rulemaking process contact Aron Borok by email or phone at 503-229-5050 (toll-free in Oregon at 800-452-4011, ext. 5050.


Your browser is out-of-date! It has known security flaws and may not display all features of this and other websites. Learn how

×