Aquaculture consulting and construction management

Five C’s Design and Consulting Inc. continues the development of innovative designs in Aquaculture and specializing in recirculating aquaculture systems.

We design specialty equipment and components with the user in mind and built to meet the challenges of continuous use is a requirement of a profitable aquaculture facility. Our experience and track record for providing reliability, energy efficiency, and low operational costs, are evidenced in the quality of every design we develop. 

Recirculating Aquaculture Systems (RAS) technology in aquaculture has grown and develop over the years. These types of system increase production, reduce operation and production costs, and you have greater control over all the typically unknown with other aquaculture systems. These developed systems have superior environmental security and environmental growth control, they improve the fish health, reduce mort rates, and improve the facility functionality.

 
We provide a full aquaculture specialty design services extending from project conception to construction completion and commissioning.  Beyond the commissioning phase, we also offer on-going operational support and training to ensure continued operational success of every facility we design.
Our approach to project planning starts with cost control within the designs, this is effective at minimizing the risks and maximizing value to our clients during the project development process.

Our Solutions Guide is designed to help you learn more about the products and services that we offer and how they may provide the solutions that you need. We have segregated aquaculture operations into four general categories:
Regulation on water use and effluent exhaust into the environment are becoming more stringent and aquaculture systems we required to be upgraded or replaced to meet these new codes and laws.

Traditionally, basic aquaculture facilities have been designed using single-pass water use strategies and are known as Flow-through aquaculture systems. Water recycle systems, involving water treatment processes, provide an alternative to traditional basic systems. In aquaculture, water recycle systems are usually classified as either partial reuse aquaculture systems or recirculating aquaculture systems which primarily differ in the magnitude of the portion of the water that is recycled, and the complexity of the water treatment processes used.

In flow-through aquaculture systems, water is passed through the culture system only once and is then discharged back to the aquatic environment. The flow of water through the aquaculture system supplies oxygen to the fish and carries dissolved and suspended wastes out of the system. Flow-through systems became a popular and cost effective approach for aquaculture when water sources were plentiful and competing uses for the water resource were low along with limited environmental requirements.

Flow-through Aquaculture Systems

Partial Reuse Aquaculture Systems (PRAS) use water treatment processes to allow a portion of the systems discharge water to be recycled and supplied back into the growing tanks. For aquaculture facilities faced with limited water resources, sustainability issues, or a requirement for improved control over water conditions, reuse technology is the next step in the technological evolution of modern aquaculture systems.

Partial Reuse Aquaculture Systems

Recirculating Aquaculture Systems (RAS) incorporate additional treatment technologies beyond those used in Partial Reuse Aquaculture Systems (PRAS), allowing for significantly greater quantities of water to be reused= with very little (1%) make-up water,  Recirculation systems afford a level of control well beyond any other technology application in aquaculture and provide significant production, system control and economic benefits.

Recirculating Aquaculture Systems

Aquaculture background and system summaries

Aquaculture Systems

Three common and basic types of aquaculture systems are summarized below. Some aquaculture facilities have variations of each or combinations of each of the following:

1. Flow through systems - When there is an abundant and easy to harness supply of clean water, a concrete raceway or pond is constructed such that the constant flow of water creates a favorable place to raise fish. For cold water species, such as trout, the source of water will usually be from a spring or artesian well. In these systems the solid waste from the fish will settle to the bottom and with some management practices the solids are periodically removed by suction. Another methods of solids management is to leave the solids accumulate at the bottom of the pond for a season or more and then drain the pond to scrape out the solids. The solids can be disposed of by spreading on land or by dewatering and used as fertilizer. The operators of flow through systems should adopt best management practices to minimize the impact of the discharge water on the receiving water from discharged of fish waste, changing the water temperature or from additional chemicals used to treat the fish. Regulations and officials are becoming more stringent on these systems and discharge water from the facilities can contaminate the downstream portion of the water source. Other items to keep in mind for these types of system are the facilities amount of control over the water source. Water quality, volume, temperature, and disease enter the facility in large quantities, and if water treatment is required the facility must treat the entire volume of water used.  

2. Pond Systems - A typical use of pond systems is in growing warm water species from fry to fingerlings. The ponds are initially filled with water and fertilized to create a natural growth of aquatic organisms to provide a natural food source for the fry. With low fish densities, they can grow for a whole season with natural aeration and some supplemental feeding. Higher densities of fish may require mechanical aeration, supplemental feeding, and a supplemental flow through water source.
One method of operation is to harvest the fingerling in the fall for transplanting into waters of the state or to another system to grow to food fish size. Ponds can also be used to grow fish to adult size for food fish of fee fishing. One method of management is to completely drain the pond to harvest the fish. During a complete draindown, the wastewater should be directed to a separate settling pond to remove stirred up fish wastes and other settleable solids prior to discharge to the receiving stream. Another harvest method is to seine the fish out with no drawdown or a partial drawdown.

3. Recirculating Systems - The advantage of recirculating systems is that a high density of fish can be kept at optimum temperatures by removing the fish waste and reusing the water. The rate of growth is usually faster and the system can be covered to protect the fish from predators. Most recirculating systems are in buildings or green houses raising warm to coolwater species. An effective wastewater treatment system will usually include a settling tank followed by a biofilter. The biofilter provides a medium for aerobic bacteria to convert organic fish waste and ammonia into their cell mass and then it is removed as a settleable sludge. Some systems will include more treatment units such as air stripping, micro filtration and disinfection. The technology for effective, reliable and economic treatment systems to clean up the water for recycle continues to improve every year. Waste discharges include solid fish waste, sludge from the biofilter and a low percentage of water dumped each day to control pollutants that are dissolved in the tank water and not removed by the treatment system. The solids have nutrients beneficial to plants and should be used as fertilizer whenever possible.

Typical Aquaculture facilities Products

The aquaculture sector is always striving to supply what their customers want. These are some typical aquaculture products produced by aquaculture facilities:

1. Food Fish - These fish are raised to adult size and sold live or ready to cook fillets. Salmon, Trout and perch are some of the common species. Some farmers add value to their product by delivering fresh fish to local restaurants, smoking their fish and retail sales at the farm.

2. Fee Fishing - Adult fish are raised in private ponds and the customers have the thrill of catching and keeping a fish for a certain fee, which is generally based on the size of the fish. Some farmers clean the fish and some even cook the fish as part of a full meal package.
3. Bait Fish - Minnows are hatched from eggs, raised in a pond and sold in bait shops to sport fishermen for bait. Some farmers use shallow seasonal ponds where minnow fry are stocked in the spring and harvested before winter. A few farmers supplement their sales by harvesting minnows and insect larvae from the wild. DNR and private farmers raising game fish for eventual stocking into the wild also purchase minnows as live feed.

4. Stocking - Fingerlings or larger fish are released to grow into catchable size sportfish. The market for stocking size fish includes registered fish farmers that want to enjoy unrestricted fishing in their own ponds. Lake associations, sport clubs and similar organizations purchase fish to stock their favorite lake even though it has public access and make receive some stocking from DNR. Lakes with no public access are not stocked by DNR, but the private landowners may purchase stockers. Stocking of any waters other than a registered fish farm require a stocking permit.

Associated Environmental Issues

Water Discharge

The raising of fish will generate excess water or waste that must eventually be discharged to surface waters or to land application. The volume of wastewater will depend on the type of system with flow though raceways generating the most discharge and recirculating systems the least. Fish waste is an organic pollutant measured as Biochemical Oxygen Demand (BOD) As BOD decomposes in receiving streams, it uses up the dissolved oxygen that wild fish and aquatic life depends on. Phosphorus and ammonia nitrogen are other pollutants in fish waste.

A Pollutant Discharge Elimination System permit regulates discharges into surface water or groundwater. A permit has concentration limitations for pollutants from fish waste, such as suspended solids, that are calculated to protect the water quality in the receiving stream.

In the U.S., the (EPA) Environmental Protection Agency, effluent limits for aquaculture facilities discharging to surface water require a permit only if one of the following conditions is met.

1. Production of more than 20,000 LB/yr. of cold water species
2. Production of more than 100,000 LB/yr. of warm water species
3. Feeding more than 5000 LB of feed/month
4. The facility is defined as a significant source of pollution

Aquaculture systems are encouraged to adapt best management practices, such as collecting all settleable solids prior to discharge, to avoid being identified as condition 4. Discharge to streams classified as "exceptional" or "outstanding resource waters" should be avoided.

Water Supply

Some area of the globe are well suited for Aquaculture because of an abundance of clean water from surface waters and groundwater. Some existing facilities are fortunate to utilize a free flowing water supply from a spring or flowing artesian well. In many parts the groundwater table is near the surface and cool clean water can be economically pumped to a fish pond. A high capacity well permit is required if the total pumping capacity of all the wells on the site exceeds 70 gallons per minute. There are few restrictions on the volume of groundwater that can be pumped. Currently the only restriction is that pumping from a high capacity well does not draw water away from any municipal well.

Water for fish raising can also be withdrawn from surface water, however some restrictions may apply. A basis legal restriction is that any withdrawal cannot interfere with the public interest in the navigable waters, the rights of the public or the rights of the downstream users. Construction of a dam or diversionary structure to accumulate water and draw it off to a fish pond may require a permit.