Located in the Pays de Caux region of Upper Normandy, Étretat is famous for its spectacular chalk cliffs and stunning beaches. It has a population of only around 1,300, but as a popular holiday destination it hosts over a million tourists every year. It goes without saying that a swimming ban on the beaches at the start of the peak holiday season would be very bad news for the local economy as well as for tourists. Unfortunately, this is exactly what happened with the fire at the local wastewater treatment plant (WWTP).
Having long-term beach closures simply wasn’t an option. We needed an effective disinfection solution, and fast.
A rapid response to a critical situation
The Étretat WWTP is operated by Eaux de Normandie, a subsidiary of SUEZ, a worldwide leader in the water and waste sectors. While the plant’s primary treatment process was not affected, the fire had severely compromised the biological process, meaning that it was no longer possible to properly remove contaminants such as organic matter and ammonium prior to discharge. The existing chlorination step was not recommendable anymore. To ensure public safety, the Prefecture de la Seine Maritime issued a decree prohibiting bathing and watersports activities at four of the area’s most popular beaches.
“Having long-term beach closures simply wasn’t an option,” says M. Vincent Busnel, Regional Technical Director SUEZ Eau France. “We needed an effective disinfection solution, and fast. We suggested Kemira KemConnect™ DEX to the municipality after being impressed by its performance and flexibility in other notable projects, including the cities of Biarritz and Perpignan,” continues M. Busnel.
“With our proven technologies and decades of experience in wastewater treatment, we knew immediately how we could help Eaux de Normandie in getting a new disinfection system up and running fast,” says Patricia Aubeuf-Prieur, Marketing Manager for Advanced Water Treatment at Kemira. “After the initial discussions, it took us just 1 week to specify and deliver the solution to Étretat. Equipment and chemicals were on site and the disinfection solution was up and running two days later, ensuring the discharge from the plant met all the required standards of the bathing directive for bacteria limits.”
An impact-free solution for the environment
KemConnect DEX is a chlorine-free disinfection system that can be used to treat all kinds of water, from raw water and industrial and municipal wastewater, to storm water overflows. The secret ingredient is performic acid, or PFA for short. Because it degrades so quickly, the PFA needs to be manufactured on site in a specially designed unit supplied by Kemira. All the customer needs to do is guarantee electrical supply, water supply to flush the system, and sufficient contact time for effective disinfection. The solution includes application support, chemicals delivery, and supply and installation of dosing equipment, as well as controlling and monitoring tools.
The DEX unit at Étretat is connected to the wastewater treatment process via a carefully selected dosing point, and the chemical reaction between the PFA and the wastewater takes place in the discharge outlet as the water travels away from the plant. By the time it reaches its final destination there is no trace of PFA left in the water, or disinfection by-products.
Without Kemira’s expertise and proactive support we would not have been able to get the plant up and running again, and therefore allow the beaches to reopen for business.
Close collaboration pays dividends
Delivering an effective disinfection solution that would allow the plant to be back in full operation and the beaches to be open for business again in such a short space of time would not have been possible without close collaboration between all parties involved.
“KemConnect DEX has proven itself for over a decade in the field, so we were confident in our solution despite the constraints on site, particularly with finding the optimal dosing point. Our team worked hand in hand with the customer every step of the way, and they ensured we had everything we needed to do our job properly,” highlights Patricia. “We worked almost as one company towards a common goal.”
“Without Kemira’s expertise and proactive support we would not have been able to get the plant up and running again, and therefore allow the beaches to reopen for business. We are extremely happy with how the KemConnect DEX solution is performing and are already considering how it could support our other plants across France and beyond,” concludes M. Busnel.
