|
|
Learning at the coalface
By Kirsten Collins
Out of my cellphone’s range and more than 50 kms from some of the end-users of the water it produces, the Wainuiomata Water Treatment plant is a key site visit for students of the Environmental Training Centre’s National Certificate in Water Treatment course, offered through the NZWETA (NZ Water and Environment Training Academy) joint venture.
Joining 12 students from around New Zealand, during one of their two week theory study blocks in Gracefield near Wellington, along with two of their tutors, Danny Allen and Sarah Cresswell, I got to see ‘behind the scenes’ at the plant and learn a little more about where my tap water comes from.
I also found out more about how the industry gets and recognizes the skills required to make it all happen, and the role that training organizations like the Environmental Training Centre (ETC) play.
On site
Alistair Forsyth, the Greater Wellington Regional Council’s plant operator for the Wainuiomata site, is tour guide and teacher for the afternoon.
Wainuiomata is the newest plant in the Council’s network, opening in 1993. It operates alongside three other treatment plants Te Marua, Waterloo and Gear Island.
As well as being the newest in its region, it is also one of the the first plants in the country to achieve an A1 grading from the Ministry of Health.
The plant’s outputs and operations are measured 24/7. During our visit Alistair comments that “people can’t fathom how effective our water purification process is”.
He also acknowledges the debt owed to the foresight of the engineers who first worked on the water supply system for the Wellington region – one section of the 5 km cast iron main that delivers water into Wellington city was built around 130 years ago and still going strong.
Alistair’s tour includes a comprehensive introductory session to the plant’s processes, before the students head off to see the action.
The Wainuiomata Water Treatment Plant
Wainuiomata Water Treatment Plant receives water from the Wainuiomata and Orongorongo Rivers and three smaller creeks. Its design capacity is 60 million litres per day, but production is typically around 30 million litres daily, which is just under 20 percent of the region’s annual total supply.
The plant is usually supplying water for Wainuiomata and, together with Waterloo Water Treatment Plant, supplies water to Wellington's business district and the city's southern and eastern suburbs.
The treatment process includes coagulation, flocculation, separation, filtration and disinfection. Coagulation and flocculation are optimized to achieve a Pin floc which is kept in suspension rather than removed by gravity like other plants in the region.
The dissolved air floatation process involves injecting pressurised water containing dissolved air into the water being treated, as it leaves the flocculation chambers.
Micro Air bubbles attach to and lift the pin floc to the surface where they form a sludge (DAF float), which is then overflowed into a waste pipe. The clean water then passes through a filter of sand to remove any remaining floc particles. Chlorine and fluoride are added to the treated water prior to distribution.
Once outside, via the highly computerized control room, the students are treated to a backwash in action, before touring the utilities that put the theoretical process into reality.
Course tutor, Sarah Cresswell, says the plant visit it is good way to show the students a number of quite unique processes.
The course is very much a specialist one, with less than 30 students per year going through the programme. As an example, the group I joined come from workplaces as diverse as the army and a dairy factory. ETC Training Manager Jonathan Mackey explains that students visit the training centre twice during their programme, for two-week theory sessions. The rest of their assessment is done through a practical workbook and workplace assessments.
At around $7000 per student to go through the programme, individual funding comes from both employers and the ITO.
“It’s an investment for employers but it offers real value,” he says.
With thanks to students and tutors of the 19-30 March 2007
National Certificate in Water Treatment course: Kevin Crosby - Masterton District Council , Ross Jannings - Fonterra - Waitoa , Keith Hogan - Fonterra - Waitoa , Mark Turner - Carterton District Council , Rodel Soriano - Watercare Services Ltd , Andi Jane - South Taranaki District Council , Mark Tucker - City Care Ltd , Andrew Phillips - Whangarei District Council , James Beresford - Sicon Limited , Lee Jamieson - Works Infrastructure , Gary Tapper - Fonterra - Waitoa , Joshua Takao - Gisborne District Council , Mark Proctor - Fulton Hogan - Balclutha , Peter McNabb - Alliance Group Limited , Karl Stevenson - Fulton Hogan - Marlborough , Jason Douglas - Nelson City Council , Georgina Hutson - New Zealand Army.
The National Certificate in Water Treatment (Site Operator)
This National Certificate is designed for people seeking to increase their knowledge and skills in water treatment. It is especially suitable if you are supervising water treatment plants that serve populations of 500 to 5,000, or working under supervision on larger water treatment systems. It covers specialist water treatment skills that include:
- the operation of water treatment and reticulation systems
- water sources and pre-treatment
- fundamental treatment processes
- coagulation, separation and filtration
- alkalinity and pH control
- taste and odour control theory
- sampling theory and practice
- waste management of water treatment by-products
- drinking water legislation and standards
Click here to find out more
|
|
|
|
