Remediation Works and River Water Quality
Please note the following statement from Sanctus Ltd:
In order to make excavations safe for the remediation, we are permitted to abstract groundwater for discharge to the River Lea. These operations are permitted by the Environment Agency.
Prior to discharge, the groundwater goes through our bespoke onsite water treatment system which ensures the water quality meets the criteria set by the Environment Agency. This system comprises a Siltbuster, oil/water separator and granular activated carbon pods.
Whilst operational, regular visual inspections are made every day of all the pumping equipment and at the discharge point to ensure that the system is operating as designed. It was during one of these checks that we became aware of the silt within the river, the operation was immediately stopped and the pumping equipment turned off to investigate the incident. Due to the recent heavy rainfall this has caused an increased flow and sediments within the groundwater, with the equipment responsible for removing silts becoming overloaded resulting in the fine silts seen in the river. We can assure you that no diesel has been released into the river.
We have taken the appropriate steps to ensure that our system has been fully cleaned and serviced following the incident, and will carry out commissioning tests informed by the Environment Agency prior to further discharge to ensure unacceptable silts are not discharged to the river.
The discharge water is sampled on a weekly basis and sent to an independent laboratory to ensure we comply with the criteria within the permit. In addition, water quality monitoring of River Lea is carried out by an independent consultant, upstream and downstream of the site on a monthly basis. A copy of the quarterly controlled waters monitoring report has been attached to provide additional information on the monitoring from May to July 2020.
We apologise if this occurrence caused concerns and thank the community for bringing it to our attention so that we could act promptly.