nitrogen concentration in the pond and the rainfall 30 days prior to the
sampling event. This was based on 7 ammoniacal nitrogen concentrations
measured between October 2017 and April 2019. The relationship has an
R2 value of 74%.
Using this relationship, the monthly rainfall from 2018 was used to
calculate monthly nitrogen concentrations in the pond. The concentration
was converted to a loading rate in kg/ha/month based on the volume
irrigated (calculated from 2018 irrigation hours and an
climate, with abundant rainfall and high sunshine hours, makes the region lush, green
and fertile.
Rainfall
Annual rainfall varies throughout the region. Some coastal areas receive less than 1,400 mm annually, while
the summit of Mount Taranaki receives around 7,500 mm.
Heavy rainfall events do occur and there can be extremes. In 2012 heavy rain caused a number of slips on
the coastal road around Mount Taranaki, including a large slip at Oākura that covered the road, burying a
REMEDIATION NZ LTD Page 7
Document No: RU-P-650-0500-A
Revision No: V1.3
Date: 1 0-9-2018
Controller: C Kay
page
Leachate & Stormwater
Management Plan
f) Any conspicuous change in the colour visual clarity;
g) Any emissions of objectionable odour;
h) The rendering of fresh water unsuitable for consumption by farm animals; and
i) Any significant adverse effects on aquatic life.
3.4.3 Climate
NIWA virtual Climate Station -38.975, 174.525 Thirty years of rainfall and
maintenance of structure
• R2/2708-3.1 Clark Peters Farms Limited – dairy effluent discharge.
2.3 Mr B Pope, Compliance Manager, in response to the question regarding Clark Peters
Farms Limited, advised that every dairy effluent discharge application is assessed on a
case by case basis and there are a number of environmental factors that are looked at
including land area, land size, and rainfall in the area.
2.4 Mr K Holswich, Iwi Representative, noted that the reporting provided by
“Therefore the calculations provided by RNZ
are extremely conservative, if not a completely unrealistic assessment of
page
10
the effects of nitrogen”. In the defence of using the 225 g/m3 concentration
I make the following points:
A) The amount a nitrogen applied to the irrigation fields is a
combination of the nitrogen concentration in the irrigation pond and
the volume of fluid irrigated. In summer there is less rainfall and
the evaporation from the pond
discharge point
and receiving waters in the Herekawe Stream. Scheduled inspections were carried out on 20 July 2022, 8
December 2022, 26 January 2023 and 6 June 2023. Notes from these visits are summarised below.
20 July 2022
On site 14:00 to 15:00 with Corteva staff. Weather was cloudy with a moderate northerly wind. 18 mm of
rainfall had been recorded over the previous week at the Brooklands Zoo station. Nīkau Contractors had
commenced demolition of the above ground structures. The site
mass irrigated, 2009-
2023 48
Figure 37 Paddock annual nitrogen application rates for Farm 1 50
Figure 38 Paddock annual nitrogen application rates for Farm 2 51
Figure 39 Paddock annual nitrogen application rates for Farm 3 51
Figure 40 Monthly mass of nitrogen irrigated 53
Figure 41 Monthly rainfall totals and median soil moistures 53
Figure 42 Estimated monthly mass of phosphorus irrigated 53
Figure 43 Total nitrogen concentration of soil samples taken from the
simulation model, developed by CSIRO,
Australia. The value of pasture ($/kg-DM) was estimated using local farm parameters
that were developed in consultation with Louise Hofmann, Taranaki FarmWise
consultant. The results of that work showed that the values of pasture in the area range
between $0.17 to $0.25/kg-DM, with an average value of $0.22/kg-DM.
Based on these values the irrigation marginal benefits were calculated for a range of
rainfall and soil combinations for three values of pasture:
monitoring year, with most
commencing irrigation in November or December and concluding in February. Rainfall recorded at the
Council’s monitoring locations over the summer irrigation period ranged between 55 % and 111% of
historical mean values. A particularly dry November and December lead to a drought being declared in
Taranaki during 23 December 2017. As a result, irrigation water demand was high during the 2017-2018
irrigation season, with a total water use across all exercised irrigation
groundwater beneath the Uruti Composting
Facility Site are moderately impacted with Chloride contamination
Site layout, hydrogeological interactions, soil types and rainfall also influence the level of
Chlorides observed in the soil, groundwater resources and the Haehanga Stream
environment
Offsite impacts have not been quantified and where not part of the scope of this report
The Uruti Composting Facility Management Plan was developed to improve the performance of the
composting