A Coronado environmental group is asking whether Hotel del Coronado tells guests and reservation holders that the ocean out front carries bacteria from Tijuana River sewage.

Emerald Keepers posed the question in its weekly water and air quality report for Sept. 3–9, published Monday, Sept. 14, in the Coronado Times. The group wrote: "Does the Hotel Del advise guests that the ocean in front of the hotel is filled with bacteria from the raw sewage from the Tijuana River? How about people making reservations — are they put on notice?"

Hotel del Coronado, the oceanfront resort at 1500 Orange Ave., has not publicly responded to the question.

The inquiry landed during a week when San Diego County health officials shut down the Coronado shoreline through North Beach. The county's Department of Environmental Health and Quality ordered the closure Tuesday, Sept. 8, citing sewage contamination from the Tijuana River, according to KPBS. The Tijuana Slough, Imperial Beach and Silver Strand shorelines also remained closed.

The county said the beach would stay closed until testing and field observations confirm the water is safe for contact, and warned that contaminated water could cause illness.

Emerald Keepers, a Coronado-based environmental organization led by Board President Dave Landon, tracks county water testing data and maintains air quality monitors on homes around the island. The group publishes weekly reports to spot patterns in conditions it says are "often worse than cities across the bridge."

At a recent Discover Coronado advisory board meeting, Ben Boyce, presenting on behalf of plant operator Veolia, said Tijuana produces about 100 million gallons per day of sewage. The South Bay International Wastewater Treatment Plant (SBIWTP) handles just 35 million gallons per day from one of three Tijuana sources. Boyce said sewage from western Tijuana is flowing directly onto Coronado's beach rather than into the ocean. The SBIWTP is being expanded to treat 50 million gallons per day, and 22 related projects are underway or being studied at a cost exceeding $1 billion, with completion expected in late 2028.

San Diego County supervisors approved $5.8 million on Tuesday, Sept. 1, for design and engineering work toward a local fix, according to the Coronado Times. That money funds planning, not construction.

Residents can check beach advisories and closures at sdbeachinfo.com or call the county's 24-hour hotline at 619-338-2073.