During the period under review, five inspection visits were carried out in relation to
consents 7470-1 and 7470-1.1. The following observations were recorded:
4 July 2013
Repairs that had been made to GND2102 by Harry Dixon of Strata Drilling were
inspected. The protective casing had been extended up by 2.65 m, preventing rainfall
runoff from entering the bore at the surface. Manual water level measurements were
carried out at GND2010, GND2102, GND2103 and GND2104. No abstraction occurred
Mangati Catchment Joint Monitoring Programme Annual Report 2021-2022
indicated by inspections and bacteriological sampling. E. coli
counts were high in all Wai-iti Stream samples, including the sample taken upstream of the
septic tank system. High faecal indicator bacteria counts are not unusual in streams which
drain developed farmland. There was no evidence of any groundwater infiltration from the
trenches/wastewater treatment system. A high enterococci count was obtained at one of the
Wai-iti Beach sites as a result of heavy rainfall prior to sampling.
downloaded. The water level data obtained from GND2102 is
plotted in Figure 4. The data is presented with the production bore abstraction data and
daily rainfall values taken from the Council’s Mangorei rainfall station, located
approximately 3.5 km south of the site.
An issue with the data being obtained from GND2103 was discovered in mid 2013.
Further investigations found that the logger had not been suspended at sufficient depth
to capture the full range of water level drawdown occurring
diversion to the New Plymouth WWTP was completed prior to 2000, only intermittent
discharges from the Inglewood WWTP have occurred, related to intense rainfall events and high stormwater
inflows. Any periods of overflow events are monitored by NPDC (wastewater only), with samples collected
and analysed by them at the time of each event.
Prior to the wastes diversion, the consent holder had been required to monitor effluent quality on a two-
monthly basis, as a special condition of discharge
mixed with sawdust or other organic material
and then piled up on the remediation pad. Any rainfall runoff and leachate that is
generated, drains into a series of ponds for treatment. Between each pond is a baffle
that skims off any floating hydrocarbons as the leachate passes through. These ponds
also treat the leachate and stormwater from pad 1 where remediated drilling wastes are
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5
stored and/or processed further. The treated liquid from the pond treatment system
Residual flow in race Retain a flow of at least 150 L/s, or a fish
salvage is to be undertaken
3371-Diversion of
water into race and
Lake Ratapiko
2 Maximum race water levels
Race water level:
Salisbury Rd: 205.20 m a.s.l
Mangaotea: 199.30 m a.s.l
Mangaotea Aqueduct: 199.25 m a.s.l
Lower Mangaotea: 199.15 m a.s.l
5 Recording of water levels and
rainfall
Water levels at the above sites to be
recorded, with the inclusion of rainfall at
the Mangaotea Aqueduct
access
jetties to the outlet grids had been constructed by the consent holder relatively recently
for cleaning and maintenance purposes.
The new outlet from the final pond was clear of debris on all of the inspection
occasions. The provision for influent splitting at the entrance to the ponds’ system had
been designed for use only under high (stormwater infiltration) flows. The influent
splitter is checked after heavy rainfall and on a regular weekly basis by the consent
holder’s contractor
taken and assess as compliant based on the results.
29 June 2020
Scheduled inspection undertaken by an investigating officer, during moderate rainfall with rainfall having
occurred since the previous night. The Kurapete Stream was running discoloured (brown) due to the
weather and the unnamed tributary was a slight, turbid grey due to quarry activities. The site inspection as
unable to be undertaken due to earthworks and electrical works being carried out. The stream and outfall of
the …