A statement from its Department of Natural Resources and Environment said tests on samples taken along the coast showed that the water is fit for swimming and other activities.
Dang Quang Vinh of the department said the water samples were obtained from 100 meters offshore at beaches, piers and other places in all four coastal districts, Lien Chieu, Ngu Hanh Son, Son Tra, and Thanh Khe.
The levels of pH, dissolved oxygen, ammonium, suspended solids, lead, mercury and cyanide were all within limits, he told news website VnExpress.
“There are no unusual changes” compared to tests done in April last year, he said.
The assurance came amid public concern as some dead fish have washed ashore in recent days.
People feared Da Nang would suffer the same fate as its northern neighbor Thua Thien-Hue and other provinces like Quang Binh, Quang Tri and Ha Tinh, where hundreds of tons of fish have washed ashore in recent weeks, apparently killed by industrial effluents.
Suspicion has centered on Hung Nghiep Formosa Steel Company, a major company in the Vung Ang Economic Zone, which admitted it has a large sewage pipe going straight into the sea though claiming all its discharged wastewater is treated.
The provinces have shut down beaches. A diver working in the company port in Ha Tinh died on April 24 after suffering breathing difficulties following a dive. Police have not revealed the autopsy results. Another diver was diagnosed with copper poisoning, and many are seeking medical help.
Da Nang, which is a popular destination among both local and foreign tourists, has promised to do further tests and publicize the results regularly in the coming time.