In the first half of October, Balneario Cerro Gordo, the beach across PR-690 from Treasure Point, failed Puerto Rico's beach bacteria test two weeks in a row. In the next round of samples, taken October 19 and 20, the Department of Natural and Environmental Resources (DRNA) flagged three other north-coast balnearios: Sardinera in Dorado, Punta Salinas in Toa Baja and Puerto Nuevo in Vega Baja. Cerro Gordo wasn't on that list. In DRNA's ten notices from mid-August through the end of October, Cerro Gordo and those three beaches never appeared together.
So switching beaches doesn't always solve the problem. On a day when the water across the street has a problem, the beach a short drive away may be fine. In a different week, the reverse can be true. The weekly notice is the only thing that tells you which week you're in.
Ten notices, one beach at a time
DRNA's Programa de Monitoría de Playas y Notificación Pública tracks Cerro Gordo as station RW-17. The Vega Alta municipality lists the balneario at Carr. #690 Km 7.1. The table below lists every notice DRNA posted between August 17 and October 30, 2026. For each one, it shows whether Cerro Gordo was flagged and which of the three nearest monitored north-coast balnearios were flagged.
| Notice posted | Samples taken | Cerro Gordo, RW-17 | Sardinera, Punta Salinas or Puerto Nuevo flagged |
|---|---|---|---|
| Aug 17 | Aug 11–12 | Not listed | Puerto Nuevo, Vega Baja |
| Aug 19 | Aug 17 | Notice states program beaches are apt | None |
| Aug 31 | Aug 24–25 | Not listed | Punta Salinas, Toa Baja |
| Sep 11 | Sep 8–9 | Not listed | Sardinera, Dorado |
| Sep 16 | Sep 14 | Not listed | None |
| Sep 25 | Sep 21 | Not listed | None |
| Oct 9 | Oct 5–6 | Not apt | None |
| Oct 16 | Oct 13 | Not apt | None |
| Oct 26 | Oct 19–20 | Not listed | All three |
| Oct 30 | Oct 26 | Not listed | None |
From August through September, Cerro Gordo didn't appear on any of the six notices. In those same weeks, Puerto Nuevo, Punta Salinas and Sardinera were each flagged once, all in different weeks. Then the pattern flipped. The October 9 notice put Cerro Gordo on the "no son aptas" list based on samples from October 5 and 6. The October 16 notice listed it again based on October 13 samples. Neither notice included any of the three neighboring beaches.
The October 26 notice was the longest of the season. It covered samples from October 19 and 20 and flagged nine beaches around the island. Balneario Manuel "Nolo" Morales at Sardinera, Balneario Punta Salinas and Balneario Puerto Nuevo were all on it. Cerro Gordo was not. Then the October 30 notice shrank to just two beaches, Balneario de Patillas and Playa Guayanés in Yabucoa, both on the southeast coast.
Taken by sampling date, the drive from Treasure Point to Sardinera went from flagged water to unflagged water on October 13, then from unflagged water to flagged water on October 19 and 20.
What a notice actually says
A typical notice names the sampling dates and then lists only the beaches whose samples exceeded the "Beach Action Value" for enterococci, which is 70 colonies per 100 milliliters of water. Enterococci are bacteria that live naturally in the intestines of warm-blooded animals. DRNA uses them as a sign that disease-causing organisms may be in the water.
A notice is a list of beaches that went over the limit. It doesn't give a score for every beach in the program. Out of the ten notices above, only the August 19 notice said outright that the program's beaches were apt for bathers. The rest only name failures. If Cerro Gordo doesn't appear on a notice, that tells you it wasn't one of the failures in that round. It doesn't mean the water passed.
DRNA's program page also says how long each result stays in effect:
"Los resultados de los muestreos reflejados en el mapa permanecerán hasta la próxima notificación."
In English, sampling results shown on the map remain in place until the next notification. That means the October 9 and October 16 flags on Cerro Gordo stayed on the record until the next notice came out. The newest notice is always the current one, so a stale headline in a group chat can be a week behind.
The water in a notice is already several days old
This fall, notices went up three to seven days after the samples were taken:
- Samples from October 5 and 6 were posted October 9.
- Samples from October 19 and 20 were posted early on October 26.
- Samples from October 26 were posted that Friday, October 30, at 1:51 p.m.
The delay comes from the testing process. DRNA's Water Quality Area (Área de Calidad de Agua) sends staff to 35 beaches that the Puerto Rico Planning Board has designated as beaches. The water samples go to the Laboratorio de Investigaciones Ambientales de Puerto Rico for incubation and analysis. A quality-control office checks the results, and a special projects division reviews them before the agency publishes the notice and issues a press release.
Notices come out several days after sampling, so they can't reflect anything that happened since, like a heavy rain or a calm, dry spell. DRNA addresses that gap with a standing recommendation. After continuous rain, it says to stay out of the water until 24 hours after the rain stops, and to keep away from the mouths of streams and from pipes that drain rainwater onto the beach. In practice, a notice and a weather check work together. The notice covers the water as it was earlier in the week. DRNA's rain guidance covers the time since.
What the 70-colony line means
The 70-colony threshold comes from federal guidance. DRNA runs the program under the federal Beaches Environmental Assessment and Coastal Health Act of 2000. In its 2012 Recreational Water Quality Criteria, the U.S. Environmental Protection Agency describes the Beach Action Value as a precautionary early-alert tool for public notification. It is set at roughly the 75th percentile of the water-quality distribution, and EPA lists 70 CFU per 100 mL as the culture-based value for enterococci.
The line is set to catch a problem early. DRNA puts it in practical terms. A beach that meets the value gets a green flag on the agency's map and is recommended for swimming. A beach that exceeds it gets a yellow flag and isn't recommended for immersion, which DRNA calls primary contact, because organisms that can affect the skin, eyes, nose, throat and digestive system may be present.
Why the flag on the sand may not match the website
DRNA sends each result to the beach's administrator. Administrators include the Compañía de Parques Nacionales, DRNA itself, municipalities and private operators such as hotels. The program page says it's up to each administrator, once notified, to decide how to physically inform the public. So what's posted at the Cerro Gordo entrance depends on the administrator's routine. The DRNA notice is the record of what the lab found.
Where to check before you cross PR-690
A few sources cover most situations:
- The newest DRNA notice. Notices are posted in sequence under DRNA's Notificaciones Ambientales category. Look for RW-17 for Cerro Gordo, RW-18 for Sardinera, RW-19 for Punta Salinas and RW-23 for Puerto Nuevo.
- The rain clock. If rain has been falling steadily, DRNA's 24-hour guidance applies whatever the last notice said.
- A phone call. DRNA's Área de Calidad de Agua can be reached at 787-999-2200, extension 3000.
- EPA's BEACON database, for history only. EPA's beach program contacts page warns that data submitted by states and territories can reach BEACON anywhere from days to months after it's collected. It's useful for looking at past seasons, not for deciding whether to swim tomorrow.
The last notice in the table, posted October 30, didn't list Cerro Gordo or any of its three neighbors. Newer notices have likely been posted since, and the newest one is the one that applies.
Many Treasure Point owners host family or rental guests who arrive with Cerro Gordo already on their plans. If you'd like help keeping guests up to date, including a link to DRNA's latest notice in your welcome information, Unique Properties Realty PSC manages Treasure Point condos and pays attention to the details guests run into across the street. Connect with Dorado's local specialists.
