
Since first surfed in the 1970s, Uluwatu becomes more and more popular, receiving tons and tons of tourist each year. It is awesome for the community economy, but tourism also means the generation of waste. Uluwatu didn't have the necessary infrastructure to manage it so all the garbage ended up in the Uluwatu cave. The beach and sea life was being destroyed. Project Clean Uluwatu, GUS, and a few local residents decided to join forces and do something about it. They removed 30 tons of rubbish from the ravine.
Next, they found a long term solution for the sewage: it not only wouldn't end up into the sea, but also would create plant life. How is that!? Thanks to the Waste Water Gardens. Here you are, another great example of how we can transform the waste into something actually useful.
BUT, WHAT ARE WASTE WATER GARDENS?
Basically they are gardens designed to repurpose the treated water from the septic tanks. They transform and use the waste into their own benefit and grow thanks to all the nutrients in the treated water. They get the chemical fertilizers' main components in a natural way.
HOW DOES IT WORK?
Every single bathroom and kitchen sink of Uluwatu is connected to Project Clean Uluwatu’s STP tank.*
*-From November 2013 to January 2014 the plumbing was completed and connected and the system began operation.
The STP tank is collocated in the east side of Uluwatu cliff. It liberates the waste from the most harmful compounds. After that the half purified sewage can be used to water the gardens.
The first water gardens were built in April 2014, and the new gardens were are still under construction. This work is an anticipation to be ready for the prediction of all the new hotels that will be built in the next years in Uluwatu. Because the Uluwatu geography -it is mainly a village in a cliff- , the gardens couldn't grow up in a big piece of land so they were distributed in boxes in different levels. The tank is at the bottom so the water has to be pumped. Once at the top, the water will be carried down through each bed, by gravity. After pass through the 21 different boxes of gardens, the water that reach the bottom will be ready and clean enough to end up into the sea don't being harmful for it.
While the sewage is flowing through the gardens, the plants take advantage of all the natural nutrients that the black water offers working as a perfect natural fertilizer. The water is never in contact with the air to prevent bad smells, mosquito breeding and human contact.
Next, they found a long term solution for the sewage: it not only wouldn't end up into the sea, but also would create plant life. How is that!? Thanks to the Waste Water Gardens. Here you are, another great example of how we can transform the waste into something actually useful.
BUT, WHAT ARE WASTE WATER GARDENS?
Basically they are gardens designed to repurpose the treated water from the septic tanks. They transform and use the waste into their own benefit and grow thanks to all the nutrients in the treated water. They get the chemical fertilizers' main components in a natural way.
HOW DOES IT WORK?
Every single bathroom and kitchen sink of Uluwatu is connected to Project Clean Uluwatu’s STP tank.*
*-From November 2013 to January 2014 the plumbing was completed and connected and the system began operation.
The STP tank is collocated in the east side of Uluwatu cliff. It liberates the waste from the most harmful compounds. After that the half purified sewage can be used to water the gardens.
The first water gardens were built in April 2014, and the new gardens were are still under construction. This work is an anticipation to be ready for the prediction of all the new hotels that will be built in the next years in Uluwatu. Because the Uluwatu geography -it is mainly a village in a cliff- , the gardens couldn't grow up in a big piece of land so they were distributed in boxes in different levels. The tank is at the bottom so the water has to be pumped. Once at the top, the water will be carried down through each bed, by gravity. After pass through the 21 different boxes of gardens, the water that reach the bottom will be ready and clean enough to end up into the sea don't being harmful for it.
While the sewage is flowing through the gardens, the plants take advantage of all the natural nutrients that the black water offers working as a perfect natural fertilizer. The water is never in contact with the air to prevent bad smells, mosquito breeding and human contact.

WHY WASTE WATER GARDENS IS THE BEST SOLUTION?
Because it creates life from waste: and the vegetation, a part of do Uluwatu more beautiful, will produce the oxygen that we breathe, destroy the carbon dioxide and host more live.
Because the results are more than satisfactory improving drastically the water quality:
- 90-95% BOD reduction (Biological Oxygen Demand). If the water has been altered by human influence it might carries excess of residue. These need oxygen for the decomposition process that is robed from other aquatic organisms who need it to live: this means less waste means more oxygen for living beings.
- 90-95 % TSS reduction (Total Suspended Solid reduction). It means reduction of non-filterable residue, the dry-weight of particles trapped by a filter.
- 45-80% Nitrogen reduction. Even if it's a vital component of life, too much nitrogen can be harmful. It can consume the oxygen that the aquatic life need to flourish.
- 30-60% Phosphorus reduction. A modest increase in phosphorus will begin a whole chain of undesirable misfortunes as accelerated plant growth, algae bloom or the death of aquatic animals.
- Over 98% Coliform bacteria reduction. It is a bacteria founded in the waste that comes from the digestive tracts of animals and humans. Its presence in the water means fecal contamination and can cause diseases.
(Data taken from wastewatergardens.com)
It is a long term ecological solution. The creation of this new green zones and its infrastructure are expected to live more than 20 years. All this time without creating pollution nor using harmful additives for the process.
Even the installation of the wetlands may be more expensive than a conventional waste water manage system, the maintenance costs are 95% lower. The design may be more primitive but, ironically, it works better and it carry less technical problems than the standards waste water systems. There is not yearly expenses in harmful chemical additives. As it has been already explained, the nutrients from the black water work as a great sustainable, natural and free fertilizer. Also a minimal machinery is needed and the only electricity used is for one of the gardens to pump up the sewage along the cliff.
And you just have to see the difference between the Uluwatu cave 5 years ago and nowadays. And it looks really cool.
Even the installation of the wetlands may be more expensive than a conventional waste water manage system, the maintenance costs are 95% lower. The design may be more primitive but, ironically, it works better and it carry less technical problems than the standards waste water systems. There is not yearly expenses in harmful chemical additives. As it has been already explained, the nutrients from the black water work as a great sustainable, natural and free fertilizer. Also a minimal machinery is needed and the only electricity used is for one of the gardens to pump up the sewage along the cliff.
And you just have to see the difference between the Uluwatu cave 5 years ago and nowadays. And it looks really cool.