A new set of water analyses has intensified the dispute over a September 1 runoff incident at Es Pouet beach in Sant Antoni, Ibiza.

Environmental group Salvem sa Badia de Portmany says laboratory tests it commissioned from samples collected on the day of the incident detected extremely high levels of intestinal enterococci and E. coli.

Sant Antoni Town Hall, however, maintains that its own official analyses showed the bathing water was suitable for use and has questioned the sampling procedure and locations used by the environmental group.

The conflicting results mean that the latest findings should not be presented as definitive proof that the official bathing-water assessment was incorrect.

Salvem sa Badia's samples

According to Salvem sa Badia, its members collected samples on September 1 at around 18:35, approximately four hours after the reported discharge.

Two samples were taken. One came from a foul-smelling pool of water that had formed on the upper section of the beach near some sun loungers. The other was collected from the seawater at the point where witnesses said the runoff had reached the sea.

The group says the laboratory results from the pool recorded more than 2,420 colony-forming units of intestinal enterococci per 100 millilitres, compared with the legal bathing-water limit of 185.

The same sample reportedly contained more than 2,420 colony-forming units of E. coli per 100 millilitres, compared with a limit of 500.

The laboratory's measurement reportedly stopped at 2,420 units because that is the maximum concentration recorded using the test.

E. coli level at the shoreline

Salvem sa Badia says its seawater sample also detected elevated bacterial levels.

The group reports 990 colony-forming units of E. coli per 100 millilitres, almost twice the 500-unit limit cited for bathing water.

The organisation says several people, including children, were in the water when the sample was taken.

These figures are from samples commissioned by Salvem sa Badia and do not represent the official bathing-water monitoring results published by the authorities.

Sant Antoni disputes the conclusion

Sant Antoni Town Hall previously said that its own analyses of the September 1 incident found the bathing water to be suitable.

The municipality reported negative results for E. coli and intestinal enterococci and said there was no evidence of fecal contamination that posed a risk to bathers.

The council also questioned the methodology used by Salvem sa Badia, stressing that official bathing-water samples are collected by authorised personnel at locations established under the applicable health monitoring protocol.

Municipality says the water came from the rainwater network

Sant Antoni has also maintained that the water seen on September 1 came from the rainwater drainage network rather than the sewage system.

Municipal services and water company Facsa carried out checks after the incident.

The council said the water had a conductivity of 526 microsiemens per centimetre, substantially below the 3,000 to 5,000 microsiemens range it associates with wastewater.

The municipality therefore concluded that the discharge originated from rainwater runoff.

It also said that rainwater can collect dirt and other contaminants as it travels through urban areas, which was one reason precautionary water samples were taken.

Why the two sets of results differ

The dispute is partly about where and when samples were collected.

Salvem sa Badia's samples were taken several hours after the visible discharge and included water from the pool that had formed on the beach as well as seawater.

The municipality says official bathing-water monitoring follows a specific protocol, including authorised sampling personnel and designated sampling points.

That means the two sets of samples are not necessarily directly comparable.

A highly contaminated puddle created by runoff can also produce different results from a formal bathing-water sample taken at an authorised monitoring point.

Salvem sa Badia says the beach should have been closed

Based on its own laboratory results, Salvem sa Badia argues that Sant Antoni should have closed Es Pouet as a precaution.

The organisation says it contacted the emergency service 112 on the day of the incident to request a beach closure and also contacted the Local Police.

It questions why the green flag remained in place for several hours after the discharge.

The municipality previously said that it did not consider a bathing prohibition necessary because its assessment found no confirmed contamination of the bathing area.

The group has released results from two other locations

Salvem sa Badia has also published results from two additional samples taken elsewhere around the Bay of Portmany.

The first was collected on September 4 at around 19:30 at Pontoon 2 in Sant Antoni harbour, near Passeig de ses Fonts.

The group reports 1,119 colony-forming units of intestinal enterococci and 137.4 units of E. coli per 100 millilitres.

Because the location is a port rather than an official bathing-water site, the bathing-water limits should not automatically be interpreted as a regulatory assessment of that specific location.

Caló de s'Oli sample

The second sample was taken at Caló de s'Oli after Sant Josep Town Hall ordered the shoreline closed following a separate discharge on September 8.

Salvem sa Badia says the sample was collected at around 17:30 near the outlet and recorded more than 2,420 colony-forming units per 100 millilitres for both intestinal enterococci and E. coli.

Those results are again the figures reported by the environmental organisation from its own testing.

The Es Pouet dispute remains unresolved

The latest results therefore add another layer to an already disputed incident.

Salvem sa Badia says its laboratory analyses demonstrate that fecal contamination occurred and argues that the beach should have been closed.

Sant Antoni maintains that its official bathing-water analyses found the water suitable for bathing and that the September 1 discharge originated from the rainwater network.

The two sides are also working from different sampling procedures and locations.

What is confirmed

The September 1 incident at Es Pouet is confirmed, as is the existence of two different sets of water-test results.

What remains disputed is the significance of those results and whether the contamination detected by Salvem sa Badia's samples represented a confirmed contamination event in the officially monitored bathing area.

For that reason, the latest laboratory results should be reported as findings from tests commissioned by Salvem sa Badia rather than as an independently established finding that Es Pouet's bathing water was legally unsafe.

The dispute now leaves open questions about the source of the bacteria, the differences between the sampling methods and the precise relationship between the runoff pool and the officially monitored bathing water.