HG's response measures to Covid-19 Alert Level 2.
An update from Managing Director Glen Cornelius...read more
An update from Managing Director Glen Cornelius...read more
My message is about gratitude....read more
An update from Managing Director Glen Cornelius....read more
A message from Glen...read more
HG is fully operational and committed to supporting all our clients during this difficult time....read more
Our Managing Director Glen Cornelius is standing for the role of Vice President on Engineering New Zealand's Board and needs your support....read more
Richard McIntosh, our Chief Operations Manager, has been instrumental in creating an important new industry body, UDINZ....read more
Branxholme Water Treatment Plant (WTP) is the sole reticulated water source for about 51,600 people in Invercargill and Bluff....read more
HG’s use of UAVs (drones) for survey grade mapping, data capture and 3D modelling has skyrocketed since we introduced them back in February 2018...read more
Jo Brosnahan was appointed Chair of HG’s Board in July. She talks here about what makes a good board, a good leader and a successful company....read more
Ben Inger is HG’s Waikato Operations Manager....read more
Thirteen of HG’s mid-career women recently completed a four-month Growing Greatness programme....read more
The design of our Parnell office received a Gold Pin at the Designer's Institute of New Zealand Best Design Awards in October....read more
Welcome to Terri Carajannis, who has recently joined us in the new role of Chief Digital Officer....read more
Congratulations to our senior surveyor, Josh Mason, on his appointment to the new role of Technical Manager – High Definition Surveying....read more
13 of HG's mid-career women recently attended the first workshop in the Growing Greatness programme run by Anne Elder-Knight...read more
We're proud of the recent recognition received for a number of different awards ranging from diversity to office design and property....read more
The Bay of Plenty's new University of Waikato campus in the heart of Tauranga city opened in March 2019....read more
Jenson Prasad is our new Auckland Airport Office Manager....read more
Congratulations to Jonathan Chambers, newly appointed as Emerging Director on the HG Board....read more
Welcome to Karen-Ann Venter, our new Team Leader - Civil Engineering in Wellington....read more
The Government’s first set of National Planning Standards (17 of them) were released on 5 April 2019 and will come into force on 3 May 2019....read more
Congratulations to our 24 technical experts who have been recognised for excellence and leadership in their fields....read more
Innovative sustainability features are the hallmark of the Bay of Plenty Regional Council's $25 million redevelopment of Regional House....read more
Vicki Taylor has joined us in the new role of Senior Programme Manager - Advisory Services....read more
A new high-level executive team has been appointed....read more
It is with pleasure that we announce the appointment of three highly talented independent directors to our board....read more
Congratulations to the three highly regarded industry leaders recently appointed to key senior roles at e-Spatial....read more
We’re delighted to announce the creation of our advisory services team....read more
Peter Affleck has joined our Wellington office in the key role of Team Leader - Building Services....read more
We’re delighted to introduce Greg Rozen, recently appointed as Technical Lead - Advisory Services....read more
Congratulations to Karen West, our General Manager - People & Communications on her appointment to the Board of Infrastructure New Zealand....read more
Digital monitoring to ensure New Zealand’s fleet of 1,100 commercial vessels is fishing sustainably is a game-changer for both the Ministry for...read more
Christchurch City Council’s transformative use of spatial technology won a significant award at the New Zealand Spatial Excellence Awards....read more
A fantastic opportunity has arisen for two independent directors to join our Board - one as our new Chair....read more
We’re delighted to announce the appointment of three senior leaders to key roles....read more
The engineering and construction industry was in the spotlight last month with the annual Week of Engineering event....read more
It was a great honour to receive an Excellence Award at the recent TVNZ Marketing Awards, for the Best Internal Marketing Strategy for the creati...read more
Earlier in the year we merged with spatial information specialists e-Spatial....read more
Harrison Grierson’s Young Professionals Group recently teamed up with Habitat for Humanity to help renovate a home for a local family in need....read more
Earlier in the year, Harrison Grierson got behind the Diversity Agenda....read more
The Week of Engineering returns for 2018 from 13-18 August celebrating the work engineers do every day, and showcasing amazing engineering feats....read more
Our traffic and transportation business unit HGT2 will come under the HG umbrella from Monday 2 July 2018....read more
Next week our Newmarket and HGT2 teams move into our new office in Parnell, Auckland....read more
An international expert in urban development has been appointed to a newly created senior role at Harrison Grierson....read more
The Week of Engineering returns this August to celebrate the work engineers do every day to improve the world we live in....read more
In just three months, our Newmarket and HGT2 teams will have a new home in Parnell....read more
HG is a participant employer in the LookSee Build New Zealand programme which aims to address NZ's need for engineers....read more
HG Senior Urban Designer, Lauren White has been appointed to a chair position on the Auckland Urban Design Panel....read more
Congratulations to our 26 employees who have been recognised for their technical excellence and leadership....read more
Change of some form is desperately needed, says our General Manager - Infrastructure Steve Finnemore....read more
Auckland currently faces some major issues. We have a growing population, a shortage of houses, and significant traffic congestion....read more
Our General Manager - Land Development, Richard McIntosh talks resilient infrastructure....read more
Auckland Transport and HGT2 (as a key consultant) scooped up the prestigious awards at the Asia Pacific Cycle Congress....read more
Harrison Grierson, along with more than 100 other companies, recently signed an open letter to New Zealand....read more
On 14 November 2017, we announced our merging with spatial information specialists, e Spatial....read more
Health and safety is always our top priority....read more
The world of engineering was brought to life across the nation....read more
We take a look at the sectors we work in, and each party's policies...read more
We enjoyed great success at the Innovate NZ Awards of Excellence last month....read more
A recent Queenstown appointment creates an immediate presence for HG in the region...read more
Two new appointments to the Harrison Grierson Board were approved at yesterday’s Annual General Meeting....read more
New appointment in HG's new Environmental Services unit....read more
HG now have a presence in Hamilton, and our Newmarket office is set to move back to Parnell....read more
Discover what the world’s humblest superheroes create every day with the Week of Engineering....read more
HG landscape architects scoop up top award....read more
Congratulations to our 14 team members who have been recognised for their technical leadership and excellence....read more
We are delighted to announce that Glen Cornelius, our Managing Director, has been made a Fellow of IPENZ....read more
We’re the first in NZ to own the high-tech Trimble SX10. It’s a game-changer in survey equipment....read more
We recently attended two awards ceremonies as finalists, and have been short-listed for another....read more
We're pleased to introduce three new senior staff in our Christchurch and Tauranga offices...read more
On 1 February 2017, we merged with traffic and transportation engineering specialists, T2, creating a new business unit called HGT2...read more
Harrison Grierson recently made health and safety history, with the highest score ever recorded in New Zealand for SiteWise certification...read more
Located in the heart of Tauranga’s CBD, our new office in Spring Street is modern, bright and spacious....read more
Rachel Ducker, a big picture thinker and highly experienced senior planner, has been appointed Planning Manager in our Christchurch office....read more
Our structural engineers have used the latest technology in two world first applications....read more
When the recent Havelock North water contamination issue hit the headlines, Iain Rabbitts became an authoritative voice on the matter...read more
In August 2011, Margaret created history at Harrison Grierson when she became our first independent director. Her appointment as our Chairman in...read more
Harrison Grierson has appointed Clare Tolan to General Manager - Survey. This completes our General Manager appointments...read more
Congratulations to our Chairman, Margaret Devlin, on her appointment as Chairman of Watercare Services Limited, effective from November 2016...read more
Our Water & Wastewater manager, Iain Rabbitts, says it was only a matter of time before contaminated water caused widespread sickness...read more
Harrison Grierson recently won two awards - including the coveted supreme award, at the New Zealand Planning Institute’s 2016 Awards....read more
We recently appointed a top specialist infrastructure manager and engineer to the newly created key role of Business Development Lead....read more
Congratulations to our 10 staff members whose promotions have just been announced....read more
Harrison Grierson independent director, Elena Trout, has been elected President of the Institution of Professional Engineers New Zealand (IPENZ)....read more
We’re pleased to introduce three new key people and an important internal appointment....read more
Cantabrians have much to be positive about, says Glen Hughes, our southern regional manager. “We can be optimistic about our future, despite"...read more
An international water expert has been appointed to a key role in our Auckland office....read more
The 30 year Infrastructure Plan was published by Treasury’s National Infrastructure Unit in October. It identifies big challenges for NZ....read more
Warren joined HG earlier this year from the Canterbury Earthquake Recovery Authority (CERA) as our Civil and Infrastructure Services Manager....read more
Our exclusive capabilities in modelling and retrofitting existing buildings are in high demand. We’re using state of the art structural analysis...read more
Quad 7 will be a striking new landmark and an important gateway building when it’s completed next year....read more
Recently proposed changes to the earthquake prone building policy means there are some important points to remember...read more
We’ve had a few new appointments to our wider team and would like to introduce you to who they are, their roles are and a bit about them....read more
Two of our senior managers were appointed Technical Directors on April 1, and 12 other staff members...read more
Our structural team is offering state of the art structural modelling techniques, with the potential to save clients millions of dollars....read more
This year, Harrison Grierson celebrates 130 years in business....read more
Harrison Grierson was proud to be finalists in this week’s Australian Financial Review Client Choice Awards 2015 in three separate categories...read more
Our water team is riding a wave of success. In the last few months, it’s received four prestigious...read more
Two experienced business leaders joined the Harrison Grierson Board in June....read more
Our Wellington, Christchurch and Manukau teams have moved to fantastic new premises this year…...read more
Kawakawa Bay is a small coastal settlement on the south-east coast of Auckland. Until the installation...read more
Adelphi House is a seven-storey heritage building built in 1928. Located in Wellington’s Courtenay Place Heritage Area, it was designed...read more
Today’s launch of a new visual identity for Harrison Grierson symbolises two years of significant positive...read more
Design work on Stages 2 and 3 of Mount Isa’s $33 million sewerage upgrade has been commissioned, with work...read more
Our Water & Waste team is enjoying three major successes...read more
Harrison Grierson has just released its fifth Sustainability Report, outlining our sustainability practices as a company...read more
A state of the art $10 million upgrade to the 70-year-old Kerepehi water treatment plant on the Hauraki Plains...read more
An explosion of work on the Christchurch rebuild has seen staff numbers grow by over 200% in 12 months for...read more
An expert in Crime Prevention through Environmental Design (CPTED) has jointly won a major New Zealand...read more
Harrison Grierson structural engineers have recently completed the complex seismic rehabilitation design of...read more
Harrison Grierson continues its role as professional advisor and design consultant on the Lakes residential project...read more
When Australasian engineering and design company, Harrison Grierson, appointed Dave Needham as its Tauranga...read more
Invercargill is one of the southernmost cities in the world. With a population of around 55,000 it’s the commercial centre of Southland and lies 18 km north of Bluff.
Branxholme Water Treatment Plant (WTP) is the sole reticulated water source for about 51,600 people in Invercargill and Bluff. For several years it was experiencing performance issues. Sometimes the water failed to comply with NZ Drinking Water Standards. And at certain times of the year, there were ‘taste and odour events’ due to seasonal changes in the water from the plant’s sole source, the Oreti River.
In 2017, with an unreliable WTP and complaints from the community, the Invercargill City Council commissioned Harrison Grierson as lead designers on a $10 million upgrade.
In a nutshell we replaced obsolete equipment, increased capacity and resilience, and reduced the taste and odour issues, said Steve Jones, our General Manager – Buildings and Infrastructure.
“The key objective was to enable Council to provide a reliable treated water supply to Invercargill and Bluff which met current drinking water standards. Our solution had to be cost-effective and practical.”
The upgrade included installing a new pump station, backwash and wash water handling systems, filter refurbishment, UV reactor, and hydrogen peroxide dosing plant to remove taste and odour, plus Granular Activated Carbon (GAC) filters for quenching of residual hydrogen peroxide.
The Branxholme WTP was a remote and complex plant, with two interlinking treatment processes running in parallel but varying considerably, challenging hydraulics and controls.
“From the outset we identified that many of the issues had a root cause in the complex hydraulics,” said Steve. “Surges in raw water flow from the Oreti River were causing disruption in the clarifiers resulting in water quality issues. Restrictions in downstream capacity were causing process units to function inefficiently and constraining production in summer when demand was high. Sudden fluctuations in treated water production were causing final water dosing to go out of spec. These factors plus many others meant it was a highly operator-intensive plant.”
Simply upgrading the plant was not enough to avoid the old problems occurring on a new system.
Of critical importance in the design process was developing an integrated control system. This would be the basis of managing all process units to ensure it functioned consistently and reliably. Implicitly understood by the design team was that disruptions to raw water or treated water were to be managed or minimised as this could create failure of compliance with drinking water standards.
Our hydraulics engineers and process designers worked closely together to ensure plant hydraulics were “innately understood” in developing the control system.
We also worked closely with the Council project team, operators and engineers to ensure the design met all their requirements and objectives. This included working alongside AFI (PLC and SCADA programmer).Some key success factors included:
Braxholme was an early implementer of the UV peroxide technology for taste and odour removal. Its UV peroxide plant is the largest municipal installation in the country. At the time the design was completed, there were no UV peroxide plants operational in New Zealand.
HG worked with Council and suppliers in developing value engineering solutions to reduce the overall project cost while still meeting upgrade objectives. These included design changes to the backwash tank waste balance tank, and clear water lift pumps.
Being able to undertake effective value engineering without compromising the integrity of the upgrade required a great depth of understanding of all aspects of the design. It’s critical to know what can be removed or modified while maintaining process reliability.
Of particular consideration was the design of chemical installations for environmental protection to avoid spills to the environment. This included designing a chemical delivery pad to provide spill protection during all chemical deliveries. We also provided double containment of high-risk chemicals to avoid spills during dosing.
The project has been successfully completed and commissioned and all project objectives for Council were met.
"By undertaking a careful and considered implementation of the process design with full buy-in from all team members we maximised the opportunities available to Council on this project," said Steve.
Council spokesperson Russell Keen, 3 Waters Operational Manager, says the upgrade exceeded expectations. “It will have long term and lasting benefits for the people of Invercargill,” says Russell. “As well as anticipating future growth demands, we saw an immediate benefit in the public’s opinion of Council from the removal of the taste and odour issues in the treated water which were causing complaints.”
Russell said that HG’s value engineering sessions led to modifications which saved Council significant capital cost and ensured the project was successfully delivered within budget and on time.
THE PROJECT TEAM
Lead designers & engineers: Harrison Grierson
Principal Contractor: UGL Limited (Australia)
Technology Supplier: Wedeco