in this high rainfall area is being investigated. The
requirement to discharge to land, in most cases, addresses cultural and water
quality concerns.
Recommended
That the Taranaki Regional Council:
a) receives this memorandum
b) agrees that from December 2022 consent holders applying for a consent renewal
will be required to immediately start discharging to land once their consent has
been issued
c) agrees that those consent holders whose consents are about to expire be
6). Contrary to historical
data, the upstream site had higher E. coli numbers, with counts 10m downstream of the unnamed tributary
lower than both upstream and the stream at the beach sites. As the Wai-iti Stream is surrounded by
farmland, it is therefore unlikely that high FIB counts were only attributed to the WWTP in operation.
Additionally, the area experienced moderate to heavy rainfall from early to mid-morning three days prior to
sampling. The accumulation of agricultural, stormwater
incorporating
odour surveys and four surface water samples collected for physicochemical analysis.
The water samples from the unnamed tributary of the Waiongana Stream indicated that the Company were
in compliance with consent defined conditions on the four occasions they were collected. It is noted that the
stormwater facility discharge to surface water, only occurs during significant rainfall events.
The Company continues to be proactive in their response to objectionable odour
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
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
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
“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
Report 2017-2020.
5.2 It was noted that Council would like to increase the number of monitoring bores,
especially within the eastern parts of Taranaki, to improve understanding of areas
where there is limited data and information.
5.3 Water allocation in the region is well within current allocation limits and monitoring
shows that groundwater levels are generally stable, with fluctuations the result of
seasonal rainfall and pumping effects. It was noted that we are already starting to see
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