The Environment Agency is still waiting for the results of tests before it is able to say what caused water in a Balcombe stream to turn bright green.
It says “thousands” of substances have been ruled out including fluorescein, a highly florescent dye used for tracing water in drains.
Rumours that a saboteur put the green substance into the stream near the Cuadrilla Resources drilling site continue to circulate in the village.
However, the Environment Agency said: “We are still waiting for some additional results from our sampling. We need to look at all of the results together in order to draw final conclusions.”
The agency, which visited the site originally accompanied by police, has detected ammoniacal nitrogen, butyl citrate and caffeine, all in very low concentrations, none of which has been used in drilling additives by Cuadrilla.
It said ammoniacal nitrogen was found in water draining into the watercourse from a pipe near the protesters’ encampment.
A sample immediately downstream showed that the ammoniacal nitrogen has been diluted and could not be harmful to river life.
Butyl citrate is found in a range of common products, such as polishes and inks.
The EA said: “We have not detected fluorescein or other dye. Typically dyes and pigments are difficult to detect, although easy to see at very low concentrations.
“There remains no evidence of any fish or invertebrate deaths as a result of this incident.”
The EA faced dozens of questions from an audience of nearly 300 Balcombe residents at an exclusive meeting for them held with the EA at St Mary’s Church in the village last week.
The meeting was chaired by seasoned environment correspondent Geoffrey Lean, now of the Telegraph.
The EA produced seven members of its staff who tried to explain their roles in monitoring Cuadrilla’s exploration activities on the village outskirts, the role of legislation and the nature of the work that the company had done this summer.
Afterwards they tried to address a series of questions from the audience, which included a few non-Balcombe residents who had managed to get in with tickets passed on to them by sympathisers.
Questions ranged from the nature of the chemicals used by Cuadrilla, to the type of gas emissions and the noise from the 24-hour drilling, about which the EA admitted it could have served the community better when infringements occurred.
Members of the audience suggested Balcombe was like the coal miners’ canary, and Sussex was about to get “fracking by stealth” with 57,000 acres of countryside destined for drill pads and horizontal underground drilling.
One woman suggest “depleted uranium drill bits” had been brought on to the drilling site at night, will another questioned the safety of the sand that was used in fracking.
The EA, however, said it could only regulate for what was applied for and not for what people thought might happen, and were fearful of.
THE EA denied Balcombe was a test case for fracking and that corners were being cut and pointed out that it was not a political body that made energy policy for the country.
Its officers said they had a very good track record of regulating industrial sites and drilling sites elsewhere, including Europe’s largest onshore drilling site at Wytch Farm in Dorset, and it was learning lessons from mistakes made in the US where damage to human health had been documented.
Chris Wicks, the EA’s environmental manager for Sussex, said it was hard for ordinary members of the public to put their trust in information sources because most seemed to have a vested interest.
But he said: “We do not have an arm behind our backs. I do what I believe is right based on a technical assessment provided by technical experts.”
Tony Grayling, the EA’s head of climate change, acknowledged the wide extent of the people of Balcombe’s knowledge and that the EA had a lot of work to do where companies were drilling and might use the controversial fracking technique.
He said the EA took human health issues very seriously and the environmental impact regime in the UK was much more robust than in the US.
He said: “We are taking this extremely seriously and will be working hard at it.”
The EA has since thanked everyone who attended the meeting, saying it was working through the feedback before publishing the answers to the questions on its webpage.