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19-21 Broad Street | St Helier Jersey | JE2 4WE
Connetable Jackson
Chairman, Environment, Housing and Infrastructure Scrutiny Panel Scrutiny Office
States Greffe
Morier House
St Helier
Jersey
JE1 1DD
31 October 2019
Dear Connetable Jackson
Quarterly Hearing – Additional Questions
Below are the answers to the questions originally asked of the Environment Minister, but which were agreed came under the Minister for Infrastructure's portfolio.
Sewage spills and fatbergs'
In light of the recent sewage spillage and fatbergs' being washed up on Havre De Pas beach and the bathing pool, please can you advise what measures will be put in place to prevent future occurrences?
One of the criticisms from local business owners in the area is that there is not enough communication and guidance from government when this happens, specifically, not being advised how this happened and what to tell customers to reassure them.
The sewage spill from Le Dicq pumping station occurred early in the morning on Monday 12 August. The network and pumps were all operating as normal however due to the heavy rainfall the system became inundated, Le Dicq Pumping station was pumping at maximum capacity to get the flows to Bellozanne for treatment.
The reason this overspill occurred is because many parts of town are on a combined sewer network taking both sewage and surface water so when we do get heavy rainfall the flows dramatically increase. To compound matters the station was due a cleaned that week to remove all the fat build up. This fat layer generally accumulates on top of the sewage level in the pumping stations and rises up and down as the pump station empties and fills. When the station was inundated this fat level rose in the station and tipped out of the emergency discharge and onto the beach. So what was a very dilute sewage spill was made much worse by the presence of this fat layer which was visible on the beach after the discharge. Coastal pumping stations all over the world are designed to overspill to the beach in emergency situations in order to prevent the sewers backing up and causing localised spillages either through manholes in the network or in private properties.
As part of our capital programme we have submitted a summary business case for inclusion in the Government Plan 2020-23 for surface water separation schemes under our Drainage request, that would reduce the amount of surface water flow going to Le Dicq. If the Government plan gets States approval these schemes will certainly reduce the risk of spills from Le Dicq.
At the time we did put messages out on social media and advised people to avoid the area for 24 hours until the tide had washed any remains away. We also had a team scour the beach to collect any of the fat that had accumulated. We do notify any interested businesses by email of any spills on the south and east coast, this group is predominantly the Islands aquaculture industry but we are happy to add any businesses that wish to be notified.
- What measures will be put in place to communicate better with business owners if it does happen again?
The best method for businesses to be informed is to be added to our email contact group. If businesses would like to be notified they can contact myself or my department (dfi@gov.je) they will be added to our contact email group who are notified within 24 hours of any spillage. Our contact group is growing as more people would like to be informed if there are any emergency spills.
Sea lettuce management trial
- How is the sea lettuce management trial progressing?
The 2019 summer season provided the GHE - Cleaning Services team with the opportunity to successfully develop its initial work, started in 2018, to harvest' sea lettuce from shallow water in St Aubin's Bay into a cost-efficient operational collection process.
Working in conjunction with the GHE – Solid Waste section a significant volume of harvested' sea lettuce was mixed with the normal green waste composting process to successfully produce a product that passed UK testing requirements for the Departments soil improver product.
In total over 800 tonnes of wet but clean' sea lettuce was removed from the Bay during the season which generally matched the available capacity for this material to be processed at La Collette. In order for the composting process to be successful and to not result in excessive odour issues at La Collette, sea lettuce has to be mixed in a ratio of approximately one part sea lettuce to nine parts normal green waste. As a result there is a limit on the capacity of the site to accept even clean' sea lettuce, which is currently 80 tonnes per week.
Regarding the beach harvesting work, the operational staff and management tested a number of techniques early in the season which resulted in two tractor-driven machines working together on wet sand, but out of the water, thus enabling a significant area of the beach to be cleared efficiently each day as required.
Although the metrological conditions during the 2019 spring/summer seasons were at a level that supported high growth of sea lettuce, it is believed by the Department that the early intervention in harvesting' sea lettuce from St Aubin's Bay as soon as it materialised reduced its ability to proliferate and adversely affect the amenity parts of the Bay as seen in previous years with similar water and air temperatures.
In addition to the Department's improved methods of sea lettuce clearance the general trend in reducing the level of nitrates entering the Bay from water courses is also believed to be helping the situation.
- When will the trial come to an end and when do you hope to report on the outcome of the trial?
In summary the GHE sea lettuce management response has now moved on from a trial' basis to form its standard operational procedure and will continue in 2020.
As the beach cleaning / sea lettuce season' normally starts in mid-May and extends to mid-September, it has finished for 2019.
As this was always intended to be an in-house' GHE operational trial no formal report was planned other than providing feedback as given above.
Whilst the general operational method of collection in now in place, the Department plans further work to investigate the feasibility of better sea lettuce de-watering before the material is removed from the slipways in order to reduce the weight and volume of material being transported and processed. This is subject to technical solutions and capital equipment funding being available, however discussions with UK and European specialist equipment manufacturers and agents are in progress.
Processing clean' sea lettuce through the green waste compost site has/is of assistance but has volume limitations and associated costs. An area for future exploration is to work with agricultural contractors and land owners to develop a viable means of the distribution of clean' sea lettuce directly onto suitable land in place of chemical fertilisers.
Yours sincerely
Deputy Kevin Lewis Minister for Infrastructure
D +44 (0)1534 448394 E k.lewis@gov.je