The Conca River storage capacity (initially 1,300,000 cubic metres) and its potability treatment plant are in the Municipality of San Giovanni in Marignano, at the mouth of the Conca River. It was built in the 1970s to supplement the other water resources in the coastal municipalities of the southern area of the Province of Rimini (groundwater and later the Romagna Waterworks) during the summer period.

Treatment
The plant treats surface water of the Conca River diverted by a traverse regulated by sluice gates. The first treatment phase consists of pre-sedimentation/sand removal in which the sand and silt are forced to settle on the bottom of a tank. A preliminary disinfection with chlorine dioxide and the addition of the reagent (which acts on the chemical structure and on the electrical charge of the particles) occurs in the same tank for the subsequent clariflocculation.

The water leaves the sand remover and goes into two tanks in parallel where clariflocculation occurs. This is the phase in which the colloidal materials still present are eliminated, also as a result of blown-in air (pulsator).

The water undergoing this procedure then goes through gravity filters with quartziferous sand bed that  eliminate the clariflocculation residue. Now the water undergoes post-chlorination – again with chlorine dioxide – in order to completely remove the remaining pathogenic micro-organisms and hence to eliminate the risk of infections.

At the end of this phase the water is transferred into a collection tank and then into the adduction and distribution networks.

All of the various phases of the plant are monitored around the clock.

Plant use is restricted to two or three months during the summertime, and its production – which can be as much as 18,000 cubic metres a day – varies according to the hydrological state of the Conca River, the demand of consumers and the state of the other sources of supply.

Rimini territorial operating structure manages the plant.

Page updated 22 August 2011