Farming company JB Thomas and Sons Limited has been convicted and fined $71,250 for unlawfully discharging dairy effluent into the environment at its Reporoa farm in November 2021.
The sentence was imposed by Chief Environment Court Judge David Kirkpatrick in the Rotorua District Court on July 17.
This is the company’s third such prosecution following similar convictions for pollution in 2001 and 2020.
The prosecution was brought by Waikato Regional Council, under the Resource Management Act, following an inspection where officers found the effluent storage pond on the property was full and had been overflowing.
The overflow had run into a farm drain that discharged into the Kopuhurihuri Stream, a tributary to the Waiotapu Stream.
The discharge also breached an abatement notice previously issued to the company by the council in 2019 directing the company to manage its effluent lawfully.
According to the sentencing notes, the defendant owns and operates a dairy farm at 3728 Broadlands Road, Reporoa. The farm has an effective grazing platform of about 185ha, milking 650-800 cows.
Effluent from the cowshed and associated yard and washdown water is piped to a sand trap below the shed and into a sump called “the octagon”, from where it is pumped to a floodwash tank at the top of the neighbouring feedpad.
When full, the floodwash tank discharges onto the feedpad and washes it down into a storage pit divided into three stages designed to separate solids from liquids. Excess liquid can flow back to the octagon or else is directed to an effluent storage pond about 380m away. The flow from the octagon is controlled by a valve next to the octagon that is operated manually.
The total storage capacity for effluent is 226,000 litres made up of 16,000 litres in the octagon, 30,000 in the floodwash tank and 180,000 in the feedpad storage pit.
The effluent storage pond has an estimated total capacity of 2931 cubic metres (that is, 2,931,000 litres) in an unlined pond measuring 54m by 20m.
At peak times the daily dairy shed wash volume is estimated to be between 49-59,500 litres per day, based on 700-850 cows and an industry average of 70 litres per cow per day.
On the morning of November 29 2021, council staff conducting aerial observations flew over the defendant’s farm.
They observed that the effluent storage pond appeared to be very full and may have been overflowing or had previously overflowed.
Staff arrived at the farm that afternoon. Going to the effluent storage pond, they observed an employee operating the slurry tanker irrigator, drawing effluent from the storage pond for irrigation onto paddocks.
Walking around the edge of the storage pond, they noted a slightly lower part of the embankment and evidence of a recent discharge, which appeared to have flowed down towards a farm drain. Liquid that appeared to be effluent was observed in the swale of the embankment.
The farm drain flows west to discharge into the Kopuhurihuri Stream 155m from the storage pond. The Kopuhurihuri Stream then flows for a further 260m to join with the Waiotapu Stream.
Water samples taken by the staff found elevated levels of both faecal coliforms and E. coli. Analysis also revealed elevated levels of ammoniacal nitrogen, dissolved reactive phosphorous, and carbonaceous biochemical oxygen demand.
The levels of E. coli were many times higher than the recommended guideline for safe recreational water contact use.
In sentencing the company, Justice Kirkpatrick referred to “poor management” and commented that “the gravity of the offending and the culpability of the defendant are moderately serious in this case”.
He added that “while not deliberate, I consider the defendant was clearly careless” and “the breach of an abatement notice is a significant offence in itself as the process of issuing abatement notices has the purpose of avoiding repeat offending”.