Briefly, the cave was discovered when a Hotel was digging a hole to build a "pozo negro" (slurry pit) to dump underground fecal matter and other ordinary cleaning agents, soaps, and chemicals...

This was many years ago, and above this famous EU protected cave a whole town has been built, all dumping untreated sewage underground.

Generally, if there is a large distance between the underground aquifer and the "pozo negro" the slurry is filtered by the ground and the aquifer is not contaminated, but if water travels direct to the aquifer through passages in the ground or the distance is low, filtration does not happen and the underground water is contaminated, contaminating the cave system.

In Cova Genovesa where a sewage pipe discharges directly into the cave water the few who dared go there (i.e. in an attempt to illegally block the illegal pipe contaminating the aquifer...) have reported a population of albino eels with no eyes living and feeding under the sewage pipe (nature's way to compensate and correct the problem).

So, long story short, there is a whole town dumping sewage underground onto Cova de Pas de Vallgornera.

The political "solution" recently published as per provided link is to get a technical opinion to state that building a sewage collection system and sewage treatment plant is non-viable as it would cause more problems than it solves (bull-####!), and that each property would have to build a certified septic tank (sealed so nothing is leaked to the environment) and this of course emptied regularly by certified trucks and s. and chemicals dumped legally in certified sewage treatment plants (see the movie ... and the reality is that the illegal mafia will dump it anywhere and the legal mafia of the "Friends and Family" of the local politicians will get lucrative contracts for all that which is involved from the installation of the septic tanks and then their ongoing maintenance and servicing...).

No doubt the Balearic Government will apply for further EU grants to "protect" Cova de Pas de Vallgornera (MY Money, OUR Money).

Cova de Pas de Vallgornera is not accessible to bona fide independent investigators and speleologist and the Balearic authorities continue to issue Licenses for access only to local interests who in the past have exploited commercially Cova de Pas de Vallgornera (including receiving lucrative below radar "contratos menores" and redirecting public money in non-transparent ways to third-parties, giving rise in my personal opinion to money laundering red flags and suspicions) and were aware of the sewage contamination, but conveniently kept their mouth shut, at least until recently when some Licenses and "contratos menores" were stopped (after investigation by Guardia Civil of the Ministry of the Interior).

Just a Mallorquin version of Gomorrah.

It will be an interesting real life movie to follow.