An investigation has commenced after an unknown blue material was discovered releasing from a drainage system onto a coastal area in the Pelham neighbourhood of Hastings on April 13.

Local inhabitants raised the alarm upon spotting the strangely coloured liquid emerging from an outlet in the Pelham district of Hastings on April 13.

Southern Water has indicated it is looking into the matter following the identification of the blue material.

The liquid was spotted in the Pelham area originating from the Alexandra Park Stream.

The spokesperson explained that Southern Water inspected the surface water outfall at the request of Councillor Horn and the Environment Agency. When the team arrived at the site, the discharge had already dissipated, but based on visual evidence and witness reports, the quantity was considered far too large to have resulted from someone simply washing out paint tins, and the inquiry will continue. They will update the agency and all relevant stakeholders.

The company stressed that drainage systems should carry only rainwater.

The spokesperson stated that this incident highlights that only rainwater should enter drains, and that in coastal and waterway areas, the infrastructure typically has no link to sewer systems, meaning pollutants placed into drains enter directly into nearby sea or water environments.

Hastings Borough Councillor Becca Horn escalated the matter through online platforms.

In a Facebook message, she asked residents in the Alexandra Park Stream drainage zone, including Ore, Tressell, Baird, Braybrooke, Silverhill, and St Helens, to contact her if they had information about major blue painting work carried out the previous weekend.

She suggested that someone may have been repainting a property, vessel, or pool.

Through social media, she questioned whether locals within the Alexandra Park Stream catchment area had observed large-scale blue painting projects over the weekend.

She further confirmed that the outfall in question functions as a combined system.

Councillor Horn explained that the outfall serves as a combined outlet taking surface water, domestic effluent from unauthorised connections, periodic untreated sewage releases when Southern Water decides to discharge these, and also acts as a natural watercourse from Alexandra Park stream, resulting in essentially a mixture.

The Clean Water Action campaign group secured a sample of the liquid and announced plans to conduct chemical testing.

Southern Water has faced scrutiny over additional pollution events in East Sussex, particularly a discharge of plastic bio-beads from its Eastbourne sewage treatment works currently under criminal investigation by the Environment Agency.

In February, Ofwat confirmed that Southern Water had met enforcement requirements from a previous investigation but stated further improvements were needed to meet legal obligations.

Members of the public shared their worries online.

Bob Selway, with twenty-five years working in the drainage sector, noted the common practice of incorrectly releasing water into marine environments rather than sending it for treatment. He observed that his experience shows many plumbers, kitchen fitters, and washing machine installations direct grey water into surface water drains that end up in oceans instead of treatment works.

Guy Arnold remarked that the colour does look rather too blue.