Huon River Hatchery
Rookwood Road - Ranelagh
Project Description
Huonville Hatchery Concept plan. (Updated 6-Aug-2008) (See Plan Atttached)
Introduction
To meet increasing demand for our products Tassal are building a new world best standard salmon
hatchery on the Huon River at Rookwood Road, Ranelagh.
This hatchery will be sized to provide 4 million smolt per annum for Tassals Tasmanian marine farms.
The attached Concept Layouts show the location and general layout of the facility.
This new hatchery will enable Tassal to reduce pressure on our current hatcheries and allow us to
delivery larger, healthier smolt to sea closer to the time of the season which provides optimal growing
conditions.
Eggs for the new hatchery will be primarily sourced from broodstock maintained primarily at the
Wayatinah and Russell Falls hatcheries.
Tassal is taking this opportunity to build a world class hatchery, incorporating all the latest
technology in smolt production as well as minimizing the environmental footprint. Our goal is to employ
all the best practices into the hatchery, which will benefit our farming operations and provide an
environmentally sustainable hatchery that both Tassal and the Huon Valley community can be proud of.
Importantly the hatchery will not discharge water back into the Huon River, but reuse it for
agricultural irrigation.
Site Selection
The Huon River Valley was selected as being the best option for the location of the hatchery with
regards availability of skilled staff, water resources and logistics efficiencies.
In response to Council advice Tassal selected a site on the Huon River downstream of the Huonville
water supply intake. As the hatchery utilizes fresh water, the site also had to be upriver of estuarine
effects in the river.
The Rookwood Rd site, which was in the process of being sub-divided, was chosen following consultation
with the Council and a site suitability selection process which considered environmental, infrastructural,
community and planning issues.
The site has been assessed by independent and Council planners as being a permitted use in accordance
with the Huon Planning Scheme for Intensive Agriculture Use Class for a hatchery.
The surrounding land use is generally orcharding, agriculture and forestry.
Project Parameters
Construction activities will commence on site in August 2008, with the egg-incubation portion of the
Recirculating Aquaculture System (RAS) being completed by April 2009, ready to receive eggs in the 2009
spawning season. The start feeding and smolt portions of the RAS will be completed by July 2009, ready to
receive the incubated ‘eyed’ fish. The first smolt delivered to the sea from the RAS will be in March 2010.
The project capital cost is budgeted at $18.5m. Apart from the RAS technology Tassal will be hoping to
source construction services and materials locally wherever feasible.
Once completed the hatchery is expected to employ around 8 full time people.
Hatchery Design
As Tasmania’s water resources are put under pressure from climactic conditions and greater usage,
existing river based flow-through hatcheries are increasingly operating with reduced river flows and
warmer water temperatures.
After an exhaustive world wide tendering process Tassal has selected a state of the art RAS technology
as provided by Aquatec Solutions (AQS) of Denmark for the hatchery. This technology recirculates water
through a series of fish tanks and treatment systems enclosed within a temperature controlled building.
The key reason that AQS were selected was because their system provided for the minimum water usage, with
the highest quality discharge of the offers received and technologies reviewed.
As the water is recirculated the hatchery draws less water from the environment and has a reduced water
discharge volume. This has the added benefit of enabling water to be more easily temperature controlled to
create optimum growing conditions for the fish.
The AQS RAS system includes for temperature control, pH balancing, oxygen addition, water filtration via
micro screens, carbon dioxide removal, ammonia removal, disinfection, de-nitrification and phosphorous
removal elements. A clean water fraction is bled off to maintain a thermodynamic balance in the system.
Both the Huon River and on-site bore water will be used to supply the hatchery, with bore water generally
preferred as the primary source, and Huon River water as a back-up. The thermal consistency and lack of
active biology within bore water makes it generally preferable for a RAS system compared with river water.
All water entering the hatchery will be disinfected with ozone prior to being pumped into the recirculation
system.
The clean water fraction discharged from the hatchery will be directed into a new 15ML lined dam, which
will store water until it is used for agricultural irrigation. This water will in effect substitute for
water which agricultural users may have otherwise drawn from the river.
Water Reuse Scheme
The two main discharges from the hatchery will be a clean water fraction and a dewatered sludge. The
sludge will be transported off site by trucks and used eventually as fertilizer. The sludge is not part
of the water reuse scheme.
Tassal has recognized that water management is a key issue and so the clean water discharged from the
hatchery will meet the Division of Environmental Management Guidelines for the Discharge of Pollutants
from STP’s to Fresh Waters as per the table below:-
| |
Unit |
50th Percentile |
Maximum |
| BOD |
mg/l | 5 | 15 |
| TSS |
mg/l | 10 | 20 |
| Ammonia |
mg/l | 1 | 5 |
| Total Nitrogen |
mg/l | 7 | 15 |
| Phosphorous |
mg/l | 0.5 | 3 |
| pH |
ph | 6.5 | 8 |
| Oil and Grease |
mg/l | 2 | 5 |
| Thermotolerant Coliforms |
cfu/100ml | | 150 |
The quantity of the clean water fraction varies with the annual hatchery cycle. The estimated
daily amount at the beginning of the hatchery cycle in October is 4kl/day. At the hatchery peak
operation in March the average daily volume is anticipated to be 242kl/day.
This water will be stored on site in a lined 15ML dam and then be irrigated onto adjacent
agricultural lands in accordance with the Division of Environmental Management Guidelines for the
Use of Recycled Water in Tasmania. It will not be discharged to the River.
The clean water fraction from the hatchery has been through the treatment measures suggested for
Class A recycled water. Due to its nature the clean water fraction discharged from the hatchery can
be used for any type of irrigation without any significant risk. The only limiting factor expected
in the irrigation system operation is hydraulic load.
The areas for irrigation have been chosen so that the prescribed buffer distances to roads, land
boundaries, natural water courses, dams and the Huon River are maintained. In addition a 100m buffer
zone has been implemented as a minimum at all irrigation property boundaries. The area of irrigation
is 16 ha and once in operation the reuse scheme will be continuously monitored to ensure compliance
with the reuse guidelines.
Available areas for future use are orchards and pastural areas on both the 3rd Rock Agriculture and
Calvert Brothers properties. There is also some limited scope for irrigation on the Tassal site.
The soil dryness index model has been used to calculate irrigation and storage requirements. Over
40 years of daily local meteorological data (from Grove) has been used to determine that the storage
will be more than adequate, assuming an irrigation rate of between 3 and 5 mm/day over a 16Ha area of
pasture. Initially crops will be restricted to various grasses suitable for grazing or cropping for
stock feed. Nutrient concentrations are so low the pasture may need the addition of fertilizer to
supplement nutrients provided by irrigated water.
Traffic
During the construction period there will be increased day time truck movements down North Huon Road
and down Rookwood Road. On average during the construction period there will be between 8 and 30 truck
visits to the site per day.
Following the construction stage and during normal production there will be an average of less than
one truck visiting the site per day (eg delivering feed, liquid oxygen and removing sludge cake) with
an additional average of 2 additional trucks per day during the autumn/winter period as smolt are delivered
to Tassal’s marine farms from the hatchery. No B-doubles are planned the visit the site. Truck movements
will generally be limited to daylight hours.
Access to the site will be via Rookwood Road, where a separate truck entry and exit arrangement will
be constructed.
Hatchery Infrastructure
The hatchery will be enclosed in a large colorbond clad shed. The size of this shed will be 90m long
x 85m wide and be around 7m tall at the apex (4.5m high at the end walls). The shed will be designed to
maintain a reasonably low profile and will be internally thermally and acoustically insulated.
Inside the shed will be:-
| • |
three separate treatment RAS systems (for incubation, start feeding and smolt stages of production), |
| • | two incubation rooms containing 10 incubation racks each, |
| • |
16 x Ø7m x 2m high concrete tanks, buried 1m into the ground, containing water and start-feeding fish, |
| • |
18 x Ø12m x 3m high diameter concrete water tanks, buried 2m into the ground containing smolt, |
| • | an office, laboratory and overnight stay section, |
| • | a feed storage room; and |
| • | a plant room and workshop. |
Trees will be planted around the perimeter of the site to visually reduce the impact of the hatchery
building on the rural landscape.
A security fence will be installed inside the tree plantings, and around the perimeter of the main
hatchery building to ensure that the hatchery maintains a biosecure barrier to reduce the risk of disease
infiltrating the hatchery. The security fence will have a black plastic coating to reduce it’s visual
impact prior to the trees growing up to hide it.
The hatchery shed itself will have disinfection stations at each entrance to ensure disease is not
transported into the recirculation system. The shed will provide acoustic protection to minimise noise
discharged to the rural environment.
External lighting will be minimized, and be low level where it is required, to maintain the rural
aspect of the site. Little, if any, night activity is likely external to the hatchery building when
the plant is on operation.
If you have any comments or queries regarding this exciting development please feel free to email
Justin O’Connor (General Manager – Engineering, Tassal) at
justin.oconnor@tassal.com.au.