Water Quality Program at the Beaches of Nosara
Providing weekly, year-round water quality data to the public and taking action to improve water quality in the area
Water quality matters!
The Beaches of Nosara (Playa Guiones and Pelada) have been recognized internationally as a top tourist destination and named the fastest growing surf town in the world.
Water quality isn't just important to our marine ecosystem, its also important to our health and economy.
What's in our water?
Rapid rates of development have caused concern regarding waste water treatment amongst community members.
Residents and visitors have reported observations of foamy, brown, and smelly water in addition to illnesses following recreational use of coastal waters in the area.
Safe beach going
In Costa Rica, only 15% of waste water is treated. Currently, the Ecological Blue Flag program conducts water quality testing twice a year.
More frequent testing is needed to supplement the efforts of this important program to inform safe beach going year-round, identify problems and implement solutions.
Our Program
The Wildlife Conservation Association's Water Quality Program samples 6 locations weekly throughout the entire year.
Including three highly used areas of Playa Pelada and Guiones, Playa Ostional, Playa Garza, and the rivermouth of Rio Nosara.
Additionally, we sample upstream at Rio Nosara and nearby estuaries after heavy rainfall events or high levels of bacteria are detected.
Water Quality Analysis
Samples are collected and analyzed in a water quality lab established in Playa Guiones, using EPA approved equipment and methods.
We test for fecal coliform and enterococcus bacteria, which serves as an indicator of the likelihood of getting sick after swimming.
Stay updated with the latest results!
Water quality results are posted on our social media accounts, Swim Guide and the Surfrider Foundation's Blue Water Task Force.
Follow us to stay updated!
Results
We've been monitoring water quality since 2020. In 2024, we carried out 51 weeks of monitoring at four locations. Additionally, we occasionally collected samples at Playa Ostional and Garza.
A majority of these tests meet water quality standards.
However, there is an increase in non-compliance with these standards, especially in the rainy season and in the Nosara River.
Where is it coming from?
We followed up on results, taking additional samples for analysis from upstream at Rio Nosara and several estuaries at Playa Guiones.
The source of contamination could be anywhere in the whole watershed for Rio Nosara, while smaller, localized estuaries are likely to be contaminating Playa Guiones.
In Guiones, the source of contamination is mostly due to domestic animal feces and improper treatment of wastewater from local residential and commercial development.
What does brown water mean?
Water contamination has been more frequent in the rainy season, when pollution gets washed into the ocean from land.
Sewage from improper septic or waste water treatment systems and animal feces are spilling into the ocean during heavy rains. Pollution may also enter the ocean through the water table with tidal changes and as a result of direct dumping into rivers or the ocean.
These excess nutrients can then also cause harmful algal blooms (or "red tide") visible as patches of foamy or discolored water. This overgrowth of algae depletes the ocean of oxygen and can be toxic, killing fish and other marine life in addition to causing health risks to humans who are exposed.
Our Recommendation
Given the probability of contracting diseases, exercise extreme caution when bathing in rivers and in the ocean in the rainy season, especially after heavy rains.
We also recommend local business and homeowners get their septic or wastewater treatment systems inspected and properly maintained. In most cases, septic tanks should be replaced with a contained wastewater treatment plant. Check out our online guide for more information and resources!
How can you help?
This project has been funded entirely by private donations and matching funds from the Guanacaste Community Fund and Harmony Fund.
We are raising an additional $15,000 to cover another year of monitoring. We need to continue testing for water quality indicators to provide swimmers with reliable information on health risks. This will also help us monitor the effectiveness of other measures we are taking to improve water quality.
Make an in-kind donation! Check our amazon wishlist for items needed. We are also regularly in need of supplies shipped from the United States. If you'd like to make this type of donation or help with shipments, please contact us directly.
Take action now!
Get your septic or wastewater treatment system checked! We recommend all local businesses and homeowners have their septic system inspected and properly maintained. In most cases, septic tanks should be replaced with a contained wastewater treatment plant.
Talk to your neighbors and share your sucess stories with us on social media. Download our wastewater guide to learn more about wastewater and how to make sure your system is working properly.
Looking for solutions for wastewater treatment?
Get access to more information and resources on our online platform at SustainableNosara.com. Technical specifications and contacts for local waste water treatment options can also be found in our public google drive folder at the link below.
What's next?
We are applying to grants to implement an educational & capacity training program, identifying solutions available in the area, and offering consultations and solutions on a case-by-case basis. To ensure the program continues into the future, donations will cover all of these costs and supplies, in addition to supporting our transition to an entirely volunteer-run program in the future.
We are also pushing for long-term plans for a community waste water treatment plant by working closely with local ASADAs, the Nosara Civic Association and Municipality of Nicoya to draw attention to this issue, starting the required process, and writing grants.
Want to add a sampling location?
Our program currently tests at four locations: Playa Pelada, the Palm Tree and Baker's Beach in Playa Guiones and the Nosara rivermouth.
Additional samples can be analyzed at a cost of $40 per sample or $2,000 per year of weekly sampling at a specific location.
Learn More
Take a virtual tour and watch podcasts and videos to learn more about our methodology. See our full report and progress reports below for the latest information.
Learn more about our organization
Visit our home page and follow us on social media to get access to all things WCA.
