23/02/2021
Matthew Young
[FYI request #14539 email]
Dear Matthew Young,
Request for Information – Local Government Official Information and Meetings Act 1987
We refer to your official information request dated 28 January 2021 for information regarding the
Trade Waste Report and Consent Breaches 2020 Calendar.
Please find the information you have requested below.
1) Whether this annual report is published publicly (either through HCC, UHCC, WWL, GW or any
other relevant agency)
The trade wastes annual report is a part of the annual resource consent report to Greater Wellington
Regional Council from the Seaview Wastewater Treatment Plant (WWTP). Whilst the TW report is not
separately published the RC report to GW is available publically.
2) The report notes 19 incidences of significant non-compliance during the 2019-20 reporting
period. Can HCC please break these 19 incidences down by consent holder?
Significant non-compliance is usually defined as sample results twice the consent maximum and we
break it down further based upon whether the discharge is greater than 5m3 per day or less which
relates to the ability of the discharge to affect our network or treatment plant. Larger discharge
volumes can potentially have more impact.
Non-compliant sample results are normally followed up by re-sampling events at the discharger’s
expense with those events normally showing a return to compliance.
The 19 noted include the following sites:
Daily discharge volume greater than 5m3
Business description and site code
Waste Management Technical Services
Waste treatment TRA20638
Mexican Supplies
Corn chip manufacture TW160013
Groenz
Sauce manufacture TRA20961
Charta packaging
Corrugated cardboard manufacture and printing TRA20640
Wellington Electroplating
Electroplater TW130027
Aluminium Extrusion Company – Anodising Anodising of window joinery – closing site now. TRA20347
Division
Daily discharge volume less than 5m3
Business description and site code
New World Lower Hutt
Supermarket TRA20521
New World Stokes valley
Supermarket TRA20630
Bostik
Adhesive manufacture TRA20641
CPC
Detergent/cleaning agent manufacture TRA21261
Te Aro Brewery
Craft Brewery TW170023
Boneface
Craft Brewery TW170021
Intergroup
Infrastructure maintenance and street sump cleaning
TRA20647
3) Can HCC also describe for each incidence of significant non-compliance during the 2019-20
reporting period the nature of the breach and the HCC response?
Daily discharge volume greater than 5m3
Breach - response
Waste Management Technical Services
Site monitored at least monthly. Elevated TPH
(hydrocarbons) Aug 2019, limit 30mg/L - monitoring
showed 76 mg/L. Had been occasional issue but changes
made to their processes and plant have remedied it. Even
when non-compliant the levels were of little or no
consequence to network or Councils WWTP.
Mexican Supplies
Site monitored bi-monthly unless non-compliance requires
a re-sample. Three issues were noted, Aug 19, Jan 20 and
May 20. Because of the lime steeping process for the corn
used the pH can be elevated above their consent limit
(10.5). A newer lime dosing system was introduced but it
has failed to provide noticeable improvements so a dosing
system to reduce the overall pH may be needed. The
elevated pH causes no particular concerns in the sewer as
slightly elevated pH (>10.5) is of less concern to sewers
than lower pH (< 5).
Groenz
The site is monitored bi-monthly unless non-compliance
requires a re-sample. There is also a wastewater flow
meter to which Council has real-time web based access. 3
non-compliance events were noted in July, October and
December 2019 related to elevated solids, COD and oil and
grease. The sites pre-treatment plant has been under
redesign to improve consistency and performance and key
components of the old system were undersized.
Performance has been affected by manual production
processes. That trapping component has been replaced
with a larger more effective unit and there has been a
significant investment (around $4M) recently in
automation. Whilst having some teething issues during
commissioning it appears to have improved discharge
quality. Council had repeatedly met with them to gain
improvements and the large user charges sums required
from the site to cover the increased load are also
motivating. Because of the nature of the load (food based)
the wastewater system has been able to readily cope with
the load.
Charta packaging
The site is monitored every 3 months unless non-
compliance requires a re-sample, there was one incident
noted in May 2020. Discharge volume is around 15 to
20m3 per day. Their pre-treatment system for printer and
corrugated cardboard production waste water is less than
ideal. It was to be replaced as part of another project but
their owners changed their mind. The end result is
occasional elevated solids levels and copper levels (from
some inks. Adequate maintenance of their system tends to
keep matters under control. Council has flagged to them
that a new more effective pre-treatment plant will be
required. The copper level whilst twice the limit did not
cause an issue with management of Councils WWTP bio
solid (where heavy metals tend to accumulate in WWTP’s)
as overall levels are well managed and below our old bio
solid limits. Note: I do not believe any plant in the country
(with or without industry) can met the current bio solids
guidelines levels
Wellington Electroplating
The site is monitored every 3 months unless non-
compliance requires a re-sample. Generally the site is
complaint but monitoring in May 2020 noted a non-
compliance for elevated Nickel (15 vs limit of 10 g/m3) and
Zinc (26 vs 10) levels. From a follow-up visit it seems likely
the issue was related to poor draining practice (manual
process) though there is the possibility of a failure to
maintain their pre-treatment dosing system which is
intended to help drop out metals. The elevated metal
levels did not compromise Councils WWTP bio solid and
caused no network or plant issues, the levels and more
importantly the masses, though non-compliant were still
relatively low.
Aluminium Extrusion Company – Anodising In March 2020 monitoring picked up that the pH was
Division
elevated (11.2 vs 10 limit). Other factors good. Meets the
definition for significant non-compliance but not of great
concern. Site has a very long history of good compliance.
Site closing in near future.
Daily discharge volume less than 5m3
Business description and site code
New World Lower Hutt
The site is monitored every 6 months unless non-
compliance requires a re-sample. Monitoring identified
significant non-compliance for oil and grease levels in Aug
2019. This prompted a number of visits and assessment of
the need to replace a deficient and damaged old grease
trap for the deli area. Replacement is not simple but New
World has not been fast to act to protect the downstream
sewer, meetings have occurred, reminders have been sent
and further action is pending.
New World Stokes valley
Sampling in July 2019 identified elevated oil and grease
levels however this was not consistent with our visit
observations. At that point in time we were experiencing a
number of issues with sampling from the lab and further
training has occurred for relatively new staff to improve
their processes. This result is believed to be unreliable.
Bostik
Sampling in May 2020 identified notably elevated COD
(Chemical Oxygen Demand) of 18000 vs limit of 2500 g/m3
and Suspended Solids (9000 vs 1000 g/m3 consent limit).
The current sample point is less than ideal and sampling
correctly not easy. A visit identified a combination of poor
sample point, possible inadequate maintenance of the first
stage trap and the need for a new larger second stage trap.
This requirement has been issued as part of their new
trade wastes discharge consent along with some other
minor changes. Discharge volume is quite low so the
significance of any issue is limited.
CPC
Elevated COD and detergent levels in June 2020.
Occasional issue of little significance given very small
discharge volume and significant dilution in nearby sewer.
Essentially they are a small scale detergent manufacturer
who wash residue from some batches to a waste tank and
periodically discharge the tank slowly to sewer. Total
discharge to sewer is usually around 5m3 per 2 months
Te Aro Brewery
The site is monitored every 6 months unless non-
compliance requires a re-sample and given the relative
newness of the craft beer industry we have also carried out
a number of proactive characterisation samples. The
November 2019 sample identifies elevated COD (16000 vs
10000 g/m3 limit) and elevated suspended solids (4300 vs
1500 limit). Site visited and improvements to their waste
handling system suggested. Discharge volumes are
relatively small and a long run of private sewer limits risks
to council sewer. Increased loads result in increased user
charges bills which tend to focus them on improvements.
Boneface
The site is monitored every 6 months unless non-
compliance requires a re-sample and given the relative
newness of the craft beer industry we have also carried out
a number of proactive characterisation samples. The
November 2019 sample identifies elevated COD (36000 vs
10000 g/m3 limit) and elevated suspended solids (11000 vs
1500 limit). We have required modifications to their waste
tank which improve the discharge and the reliability of
sampling given there was the potential to sample
incorrectly. Brewery discharges tend to be high in COD
(10,000 g/m3 is common) and solids can be elevated.
However the material is readily treatable in our WWTP.
Intergroup
Sampled twice a year. December 2019 sample identified
elevated solids levels (4200 vs 2000 g/m3 limit). Possible
to miss-sample the setup however a visit identified a
number of improvements were needed at the site
including modifications to the trap (done) and additional
bunding to protect the storm water system. More recently
the regional council and ourselves have required a number
of other improvements to protect the storm water
network and upgrade the wash areas (to the sewer trap
system).
4) Can you also please seek for me the number of incidences of significant non-compliance per
year for the previous 5 years?
Period
Sig non-compliance (includes
Comment
sites both greater than 5m3
per day and below.)
July 2019 to June 2020
19
July 2018 to June 2019
23
July 2017 to June 2018
10 *
See below note
July 2016 to June 2017
12 *
See below note
July 2015 to June 2016
18
Note that due to multiple successive staff changes at the independent testing laboratory following a
retirement there has been a prolonged period of missed sample events and less than ideally taken
samples. We have gone to significant efforts with the samplers to help them understand some of the
tricky sites and general principles but wastewater sampling is not an exact science. However we have
increasing confidence now.
You have the right to seek an investigation and review by the Ombudsman of this decision.
Information about how to make a complaint is availab
le at www.ombudsman.parliament.nz or
freephone 0800 802 602.
Please note that this letter (with your personal details removed) will be published on the Council’s
website
Yours sincerely,
Hutt City Council
