Northumbrian Water Ltd, of Abbey Road, Pity Me, County Durham, was also told to pay costs of £3,802 to the Environment Agency, which brought the case. The company was also ordered to pay a victim surcharge of £1,000.

The court heard how on 13 March 2012 a member of the public contacted the Environment Agency through its incident hotline to report that there was raw sewage in the Ouse Burn at Callerton, Ponteland.

An Environment Agency officer tried to attend the scene that evening but failed to locate the incident in fading daylight. More officers visited the burn the following morning, where they located the source of pollution, about 200 metres downstream of Armstrong Street, Callerton. The discharge was from a combined sewer outfall with a flap valve next to Pipe Bridge over the Ouse Burn, which was believed to be part of the Northumbrian Water Ltd sewer network.

The officer saw that the discharge consisted of raw sewage, which included faeces, sewage litter, sewage fungus and effluent. The majority of the discharge was a grey colour with a strong sewage smell.

Two hundred metres downstream, officers found grey fungus across the whole bed of the Ouse Burn. Upstream of the discharge, the water was clean and clear.

The environment officers contacted Northumbrian Water Ltd, and when they attended the scene, formal samples of the discharge were taken. The greater the biological oxygen demand in the water, the greater the pollution and the water is less able to support life. Officers also took field readings of dissolved oxygen in the watercourse using a dissolved oxygen meter.

The sample taken five metres upstream of the discharge confirmed biological oxygen demand of less than 2.9 milligrammes per litre. The sample from the discharge point confirmed biological oxygen demand levels of 450 milligrammes per litre.

Following investigations in the local area the officers concluded that the pollution was most likely to be from the sewer pipe. 

Negative impact on ecology

The dissolved oxygen readings taken below the pipe bridge were all low enough to cause a significant negative impact on the ecology of the Ouse Burn.

On the 6 July 2012 representatives for Northumbrian Water Ltd attended Environment Agency offices in Newcastle where they were interviewed under caution. They explained that after receiving a call about the discharge, at 11.49am on 14 March, staff attended and were at the location just over an hour later. 

Northumbrian Water Ltd said staff found the blockage in the pipe that caused the sewage to leak at 1.10pm which was cleared within a few minutes. They explained that the manhole cover that should have been over the outlet was missing and that they had been unaware of the existence of this outlet. The reason for this was, they explained, that when they had taken over responsibility for water and sewage from the local authority, this particular outlet had not been shown on the plans provided to them.

They accepted that there had been a discharge from the outlet but argued that the degree of pollution caused by this alone, did not cause a category one pollution incident, which, on a scale of 1 to 4, is the worst level of pollution. 

The outlet at the Ouse Burn has now been permanently stopped so that there cannot be a repetition of this incident.

The day after the discharge was found, an Environment Agency officer went back to the scene to assess the impact on the watercourse. The officer found a thick covering of sewage fungus for one kilometre downstream of the original discharge point. There were dead invertebrates present at all the downstream sample sites and in the stream in between sites.

Approximately 40 metres downstream of the pollution source, effluent from a pig farm was observed discharging into the Ouse Burn via a drain from the property and a small tributary running alongside the property. Samples could not assess the long term impact of the pig farm at this time as any impacts were being masked by the sewage discharge.

Another investigation in November found that the sites downstream of the discharge had recovered since March indicating that the pig farm was not the cause of the impacts on the burn observed in March and the discharge from the Northumbrian Water Ltd outlet was the main cause of those impacts. 

Northumbrian Water Ltd responded quickly to Environment Agency contact and fully co-operated throughout the incident. 

The lead officer for the case at the Environment Agency said: “We take cases of pollution to watercourses seriously due to the environmental damage that can be caused. If anyone witnesses any pollution in their local watercourse, they can report it to our incident hotline on 0800 80 70 60.”