An "eruption" which took place in the water near Girvan yesterday, sparking nationwide speculation as to its cause, has been explained.

Yesterday [October 31], a photographer captured footage which showed the sea boiling and bubbling like a "witches cauldron" just a mile south of Lendalfoot.

The strange phenomenon sparked much attention, with people eager to find out what was behind it, however Scottish Environment Protection Agency (SEPA) have since confirmed that the incident was due to a routine discharge of treated landfill leachate into the sea.

Leachate is rainwater which has come in to contact with waste within a landfill. In this case, it came from Straid Farm Landfill in Lendalfoot.

Before being released into the environment, the rainwater is treated and sampling is carried out to ensure it has "no adverse impact" on the water.

The reason why it was more obvious than usual, and created such a stark sight in the water, was beause of the heavy rainfall over the last couple of weeks which meant "an increased volume" of leachate needed to be treated and discharged.

A spokesperson for SEPA said: “SEPA is aware of reports of a visible upwelling off the coast at Lendalfoot, South Ayrshire, on Sunday, October 31. This is a routine permitted discharge of treated landfill leachate from Straid Farm Landfill.

“Leachate is rainwater which has come in to contact with waste within a landfill. It is collected within lined containment cells and then treated prior to discharge to the environment.

Ayr Advertiser: Credit: Paul YoungCredit: Paul Young

"In advance of discharging, the operator is required to undertake sampling to ensure it meets the strict quality limits outlined in their SEPA issued Pollution Prevention and Control (PPC) Permit.

"These limits are set on a discharge specific basis to ensure no adverse impact on the receiving water body."

They continued: “Given the heavy and sustained rainfall over the last couple of weeks there has been an increased volume of leachate needing to be treated and discharged.

"This will have resulted in a prolonged discharge and more noticeable visual impact than normal.

“SEPA will continue to monitor compliance with the operator’s permit.”

Upwelling is an amount of liquid rising up causing a visible impact in the seawater.