New Zealand's only large-scale American style feedlot has been "technically non-compliant" for three months but is yet to be fined or prosecuted.
The Five Star Beef feedlot in Ashburton, owned by ANZCO, can farm up to 19,000 cattle on less than one square kilometre.
It has been there since 1991 and has been required to submit an report to Environment Canterbury (ECan) since at least 2005.
But its 2017 report was missing several key measures.
ECan's Ashburton zone lead Janine Holland said: "Annual volumes of manure they're applying per hectare and its location on site, groundwater quality, monitoring of bores, and current and proposed management practices for the feedlot."
Ms Holland, despite having intimate knowledge of the feedlot's consent, said she didn't know why Five Star Beef had omitted the data.
The feedlot was widely criticised earlier this year, particularly by animal welfare groups, as having no place in a clean, green New Zealand.
Ms Holland described the feedlot as "technically non-compliant" because she said there was no evidence of environmental non-compliance.
However, there could be environmental non-compliance in the yet-to-be reported data.
Victoria University ecologist and senior researcher Mike Joy said red flag should come up when such a report made its way to a compliance officer's desk.
"What's completely lacking in the report is any methodology. Any freshwater scientist who looked at it would just walk away shaking their head going, 'We don't know what's happening here'.
"This report is so lacking in detail we can't be sure what's happening."
It is now known how the data is measured.
ECan does not do its own identical tests to ensure the feedlot's self-reported data is accurate.
"The onus is on the consent holder to prove their compliance. It's a user pays system," Ms Holland said.
"We've got nearly 20,000 consents that we monitor across Canterbury."
Mr Joy said the feedlot's water bore samples were in excess of guideline values and several did not meet World Health Organisation limits for drinking water.
"So you could glean a little from it, but you could drive a truck through the gaps in the methodology."
There were repeated instances of copy-paste mistakes in the 2017 environmental report Five Star Beef provided to ECan. Some were very basic - the 2017 report's contents incorrectly read "2016".
Last year the feedlot's effluent pond overflowed in July, breaching its consent conditions. No enforcement action was taken.
Instead ECan made changes to the feedlot's conditions to allow it to happen again.
"It's a temporary measure, part of the action plan that we're undertaking with Five Star Beef, which will be reviewed in December this year."
Mr Joy said that response is "indicative of a council that's not taking environmental issues around freshwater seriously".
Ms Holland said her team preferred to "work with" consent holders rather than issue penalties for non-compliance.
"We're working through remediating the data omissions and the other information that we need, and sorting those things within an appropriate time frame.
"And then we will be able to identify whether we need to take any further action."
ANZCO declined to be interviewed but in a statement its general manager of livestock and agriculture Grant Buntin, disputed ECan's version of events.
"This monitoring was addressed, and subsequent sample results were shown to be within consent parameters.
"Despite occurring in 2017 and being rectified, the non-compliance notice remains in place for a full calendar year and will expire at the end of 2018."