PROJECT: The construction of concrete reservoirs in PVC formwork for aquaculture PISCICULTURE McKENZIE, Notre-Dame-des-Bois, Quebec
Mr. Maurice McKenzie
107, route du Parc
Tél. (819) 888-2654
Fax : (819) 846-0833
On 15 July 2010, Pisciculture McKenzie received Federal Government support for an experimental project which consisted of building three concrete reservoirs in PVC formwork specifically for fish breeding. Laboratory tests were undertaken to verify that the PVC respected the standard (NSF-61) regarding drinking water.
McKenzie Pisciculture is owned by Suzette and Maurice McKenzie and is in operation since 1993. It supplies brook trout for seeding to several outfitters in Quebec. Pisciculture McKenzie has 5 ponds which hold between 40,000 and 75,000 fish each. Pisciculture McKenzie presented to MAPAQ a plan to expand operations in the fall of 2009.
The project consists of building three reservoirs for fish breeding made with the technology developed by DC International. This technology needs modifications and tests in order to ensure that it responds properly to the demands of this industry.
It was therefore necessary to adapt the forming system in order to build reservoirs of PVC/concrete for Pisciculture McKenzie. The forming system has already proven itself in construction of housing projects but in this situation must be adapted to produce reservoirs that are waterproof with a smooth interior. The basic technology that is the forming system for buildings has been patented by Bernard McNamara in Canada, United States, Mexico, and Brazil in the last few years and are still in effect. More specifically the project aims to adapt the tooling, to prepare samples of components, to produce a study on the permeability, on the nonproliferation of bacteria, on drinking water standard, on chemical resistance, on the isolation in the walls, and on necessary calculations concerning structure.
Pisciculture McKenzie was therefore interested in using the technology modified by DC International which consisted of concrete tanks put in place in a permanent PVC forming system. This promising system has the advantage of building reservoirs quickly and simply and the PVC lining assures a maintenance free finish which is free of imperfections at a cost similar to the usual membrane that must be replaced every five years.
The three tanks for stocking and classification of fish are 10 meters diameter by two meters deep in the center. The walls are 20 cm thick and are made of 15 cm of concrete as well as 5 cm of insulation which is inserted in the forms at the factory. These reservoirs are therefore solid, waterproof, maintenance free and insulated in order to control the temperature of the water.
More precisely, it consists of building three tanks of 100 cubic meters capacity each with the technology of DC International. This manufacturing company has developed a PVC forming system which permits the construction of big reservoirs however this technology has never been used in the field. It has then again been used for more than 10 years in the construction of reinforced concrete housing.
The company Digigraph Systems Inc operating under the name of DC International has developed, manufactured and marketed techniques for the prefabrication of buildings made of reinforced concrete for more than twelve years. Its main market to this date is the housing market in developing countries. DC International is known in several countries and presently works with representatives on several continents.
At the beginning of 2009 one of the representatives from South America opened up a new market which was the manufacturing of a system for the realization of big reservoirs for the pisciculture industry in Chile. The DC International forming system offered more variety in regards to the walls and as a result to the reservoirs. DC International has thus built a demonstration tank of three meters diameter in 2009 in Chile. The clients were very satisfied and requested some modifications in order to render the tanks waterproof, bacteria free and smooth on the inside. The success of this project will enable benefit the Canadian pisciculture industry.
There exists a demand for this type of reservoir here in Canada and also in foreign countries. Therefore, DC International proposed to supply the reservoirs to Pisciculture McKenzie specifically for its project of expansion, proceeded to modify the tooling, and underwent the tests of the Centre de recherche Industrielle du Québec.
There exists only two other forming systems of PVC in the world. Nuform System of Toronto (formally called Royal Technologies) and Octaform originally from Scandinavia and now manufactured in western Canada. The Nuform System cannot be adapted for reservoirs because the geometry of its sections.
The Octaform System is more easily adaptable to round reservoirs and in fact some have been built in Nova Scotia. However they have not modified their profiles and because of the interstice between profiles bacteria can grow there. Because of the modifications brought about by DC International to its equipment the tests performed by the CRIQ showed the nonexistence of bacteria growth. Also the Octaform System has been found not to be totally waterproof. DC International is determined to eliminate these two problems.
Based on input from the industry, DC International went ahead to research and thus modified its profiles so there would be no space between the profiles to enable bacteria growth. DC International manufactured prototypes specifically for those involved in fish farming using reservoirs. The industry was satisfied with the prototypes. At this point DC International has modified its tooling in order to build three tanks of 10 meters for Pisciculture McKenzie.
DC International has experience in buildings of big dimensions however we must provide specific studies for the use of these types of reservoirs to satisfy the Canadian pisciculture industry. DC International has also commissioned an engineering firm a structural analysis for this purpose.
It is also important to have lab tests done to show that the PVC profiles will not permit bacteria growth according to standards and will resist chemicals and that the walls are resistant the elements.
Large waterproof reservoirs of PVC for pisciculture makes production more efficient in regards to fish farming as compared to the use of ponds as is done in Canada. For one, it is done in a controlled environment. The quality and temperature of the water are continually supervised. It is easier to abide by the requirements of the STRADDAQ (Stratégie de développement durable de l’aquaculture en eau douce au Québec) than with ponds.
Of note is that the forming system uses 80% post industrial recycled PVC. The Octaform system does not permit its use because of its geometry and thickness. Therefore DC International system promotes accepted standards of sustainability.
Large reservoirs for pisciculture reduce the use of water as they also serve as bio filters that regenerate water. The need for new water is less. Breeding ponds, on the other hand, can affect the environment and contaminate groundwater.
The owner Mr. Maurice McKenzie assumed the coordination of the project. At the beginning Mr. KcKenzie dealt with the engineering firm SMMC of Windsor. The firm Léo Barolet & Cies was then contracted to undertake the excavation, the slab on grade and pouring the concrete in the PVC forms.
DC International provided a structural technician named Mr. Serge Beauchemin and the management of the project on a technical level was given to Mr. Bernard McNamara, the inventor of the technology and the president of DC International. He is very knowledgeable in this area and has participated in various projects using this technology in Canada and overseas.
The study regarding structure has been given to the structural engineer Mr. André Bergeron. The analysis that touches permeability, growth of bacteria, drinking water and chemical resistance were done by Centre de Recherche Industrielle du Québec. The Centre de Recherche Industrielle du Québec is world-renown and had preformed the initial tests in 1997 on the forming system.
Extrusions Omnitech Inc performed the first trials for DC International. This company has worked with DC International for the past five years and is presently the principal supplier to DC International. The modifications to the tooling were done by Omnitech Inc., ARM Automatique Inc. and Prostamp Inc. These modifications enabled the manufacture of waterproof profiles which do not allow for the proliferation of bacteria.
The insulation panels that were inserted in the forms were produced according to specifications by the company Fransyl. DC International used their own technicians, and also, contracted Construction Marc Lamontage Inc. for the installation of the forms.
Placing the concrete slabs on grade was done on October 12th by the firm Léo Barolet. This company also installed the dowels in the slab (steel rods for the joining between the wall and slab) and installed a waterproof joint of flexible PVC.
On the 14th of October DC International put in place the scaffolding, all the PVC forms for the first tank including the reinforcing steel bars in the walls. Unfortunately because of the workers and the weather they could not proceed. Work resumed the 8th, 9th and 10th of November and all three reservoirs were done by 12th of November.
The concrete was put in by the firm Léo Barolet with a pump equipped with a boom. Mr. McKenzie before the casting of concrete installed the sleeves in the wall to be able to unite the various waste ducts.
During the following week Mr. McKenzie contracted an excavation firm to bank up the walls of the tanks and to prepare the protection for the winter. The tanks will be filled only in the spring.
The tests undertaken by the CRIQ have shown that the forming system made of PVC manufactured by DC International respect the standard MSF-61 regarding drinking water. This type of construction can be used in all confidence for fish farming.
The work carried out has led to the observation that the PVC profiles do not release metallic elements, phenol derivatives, volatile organic compounds or residual vinyl monomers into the water beyond the level of concentrations prescribed by NSF/ANSI Standard 61-2010. In addition, the PVC profiles do not promote the bacterial growth on their surface.
Mr. Daniel Grenier, ing. Chemist CRIQ December 2010
We are convinced that this technology is entirely adapted to our requirements and that the reservoirs built are of top quality as well as being very favourable in terms of installation, upkeep and conforming to proper standards. The process of erecting these reservoirs was quick and without specialized labour. It took a day by reservoir to install the components of PVC and the reinforcing steel bars.
This technology is very interesting for Pisciculture McKenzie and also for the whole industry here in Canada and abroad. This technology enables the construction of large reservoirs of concrete quickly with a non-specialized workforce and at a competitive price.
The interior surface which is of PVC is resistant to corrosive elements and is maintenance free. The smooth surface protects the fish from scratches or injury. There is no limit in size and no supplemental cost for one size or another. As well this system can be used for circular and orthogonal reservoirs or tanks used as bio-filters.
In conclusion, we are satisfied with the technology of DC International and with the financial support from Fisheries and Oceans Canada which covered certain manufacturing and laboratory costs.