Water purification and regeneration

Purification performance

Zero spill objective for wastewater.

With this objective in mind, the complete or partial remodeling of first-line drive stations, the substitution of critical elements, and the provision of tele-management and safety equipment are carried out.

Improvement objective for the quality of treated water.

Given the age of the sewage treatment plants in the municipality of Calvià (Santa Ponça, Peguera and Bendinat( stations are 20 years old, while Calvià’s is 40 years old), the treatment units are remodeled/refurbished and obsolete technologies are substituted to improve the biological and technical processes and achieve the improvement in the quality of water leaving them, to fulfill all the sanitary and environmental requirements.

Peguera and Bendinat subsystem:

• Remodeling of pretreatment: the expansion and automation of the entrance of both treatment plants is addressed. This will allow a much more effective separation of the solid waste that accompanies the wastewater, in particular the "wet wipes" that generate so many problems in the using of wastewater, and may ultimately affect the quality of outflow.
• Elimination of nutrients: phosphorus is eliminated by ferric chloride dosing, and the current reactors are changed to a new configuration that will allow the biological elimination of both nitrogen and phosphorus.
• Improvements in the process of the dehydration of sludge: by final generation centrifugal machines and storage hoppers of dehydrated sludge
• Additional Secondary Treatment (TAS): the current legislation presents clear requirements regarding the quality of water leaving for the sea. This quality is clearly achieved through the current biological processes, having implemented an Additional Secondary Treatment (TAS) for the microbiological refining of the exit water.
• Energy optimization objective: provision of elements to improve energy consumption in wastewater treatment plants.

• Improvement objective in air quality at wastewater treatment plants: through the placement of filters and technical improvements of existing equipment.

Santa Ponça Subsystem:

Optimization of the deodorization system of the Santa Ponça station, which was launched in October 2015.

Bendinat subsystem:

The Bendinat treatment plant is located just 100 meters from private homes, so the required demand, in terms of air quality, is extremely high, in order to avoid any inconvenience to its neighbours. Thus, despite having a chemical deodorization system operating at full capacity, a new biological system has been added and the following steps are being taken:

• Location, isolation and direct treatment of the most relevant emission points (impulse discharge zone, sieves, entrance work and laminate pond).
• Fine-tune the air by biotrickling it with pine bark.

Objective of environmental improvements.

• Within the environmental aspect of the purification facilities, the work of conditioning the submarine emissaries of the municipality is emphasized to ensure its continuity and watertightness along its route. All this has been done within the campaigns of structural monitoring and maintenance of evacuation conduits.
• At the same time, the experimental seawater agitation system at Palmira beach has been improved, to avoid the proliferation of microalgae in the bathing area, achieving very positive results.

Motorized valves have been placed in the suction pipes of the digester, replacing the existing manually operated ones, which can be operated from a computer or mobile devices. Thus, if there was a spill or a problem with this digester, it could be isolated without the need for the operator to go down to the basement, avoiding the consequent danger that the emissions of polluting gases could cause.

Utilization of reclaimed water

In clear commitment to the full reuse of the reclaimed waters of the municipality, Calvià2000 has launched a series of medium-term proposals that will make it possible to avoid the discharging of purified water into the sea, and to allocate this flow rather, towards irrigation and water use. Urban uses with full sanitary and environmental guarantees.

There is an advanced tertiary treatment system at the Bendinat treatment plant, which facilitates the use of 100% of the water, treated by this system.

During the year 2017, 144,539 m3 of regenerated water was produced.

Goal to improve the performance of the reclaimed water network.

Based on the improvement of network elements and service connection to the areas with the worst results. For this reason, general meters have been installed to control regenerated water distributed at several critical points in the network, to facilitate the determination of consumption by sectors, as well as the detection of possible leaks or irregular use.

The length of the reclaimed water networks managed by Calvià2000, by population centers is as follows:

Tertiary plant in Bendinat

The destination of regenerated water in the tertiary process of Bendinat is fundamentally the irrigation of Calvia’s public gardens.

In the refurbishment process of the Bendinat WWTP, it will be equipped with ultraviolet and microfiltration equipment, which will double the production capacity of quality water 1.1. (RD 1620/2007).