The Santa Catarina Environment Institute has classified 199 of 260 monitored coastal bathing points as suitable for swimming in its latest weekly water-quality update. The figure represents 76.5 per cent of the locations covered by the state programme.
The update was issued on 23 October after collections earlier in the week. It covers a broad shoreline network in 28 coastal municipalities and more than 100 beaches and bathing areas. The total is a count of defined monitoring points rather than a count of whole beaches, an important distinction where a single beach can have several locations under observation.
Results in Florianópolis
In Florianópolis, 61 of 88 monitored points were placed in the suitable category, or 69.3 per cent. The remaining 27 city points were classified as unsuitable. Across the other coastal municipalities, 138 of 172 points were suitable, a share of 80.2 per cent. Together, those figures produce the statewide total of 199 suitable and 61 unsuitable locations.
The numbers therefore give a more precise picture than a simple verdict on a named beach or on the coastline as a whole. A location may be beside a river mouth, a drainage outlet, a busy central stretch or a quieter section of shore. It is the individual sampled point that receives the category. A suitable result at one point does not automatically assign the same status to every part of that beach.
How the classification works
The weekly categories are based on the bacterium Escherichia coli. A point is considered suitable when at least 80 per cent of samples from the previous five weeks contain no more than 800 E. coli per 100 millilitres. A point is classified as unsuitable if more than 20 per cent of that group of samples is above 800 per 100 millilitres, or if the latest sample is above 2,000 per 100 millilitres.
That framework makes the result a point-specific assessment based on a rolling set of laboratory results. It should not be read as a permanent judgement on an entire beach, nor as a prediction that the same condition will continue unchanged after the sampling dates. The current release is a snapshot of the categories produced under that test.
Sampling coverage matters
Collections took place on 19, 20 and 21 October at 258 points. Two designated locations in Florianópolis, identified as points 95 and 96, were not collected because access was unavailable. The statewide tally covers 260 locations in total, with 199 suitable and 61 unsuitable. The difference between the sampling count and the total is a relevant limit when interpreting the week’s statewide figures.
The programme was in its fourth consecutive week of weekly sampling. This early-season run gives beachgoers and local authorities a current point-by-point reference, while later weekly results will be needed to show whether the pattern holds. The next update may change the category at an individual location as fresh samples are added to the five-week assessment.
For now, the main statewide finding is that just over three quarters of the monitored points were in the suitable category on the reporting date. The city result was lower than the figure for the rest of the monitored coast, but a citywide percentage cannot replace the status of the precise point someone intends to use. The location-level result remains the meaningful measure for a decision about entering the water.
