Containment is a buzzword in most industries in which a single spill could cause serious damage. Without proper containment plans and equipment, it’s impossible to know for sure that you’re not risking damage to the environment. The water in a hydroponics or fish farming operation isn’t exactly hazardous waste, but it is too rich in nutrients to safely release into most areas. If you plan to find a legal discharge arrangement for extra water generated by the system, you’ll need to at least process it to ensure there are no issues with algae blooms or nutrient overload.
What is Primary and Secondary Containment?
Primary containment is the main method of holding and storing the water used in this system. This includes the water currently running through the active parts of the aquaculture design and any water you store at the end of the process. Primary containment methods include the various tanks, ponds, channels, trenches, raceways, and other vessels that hold water. While a tough tank or lined pond may seem secure, it’s not enough for risky fluids like the liquids in aquaculture. This is where secondary containment comes in. Double-walled containers, lined catch basins, and spillways around an in-ground pond all serve as secondary containment measures.
Risks of Leaks and Seepage from Fishponds, Raceways, and Tanks
Increasing the number of fish being produced in each pond or tank also increases the nutrient concentration of the liquid. If crops are grown instead, the nutrient rich water is surprisingly risky to release out into the open environment. High ammonia and nitrogen levels are the two biggest risks of wastewater. Both fish and plant systems can produce these problems. Diseases also tend to spread from concentrated fish rearing operations that discharge water directly into nearby streams or lakes. Finally, any medications or chemicals used to treat the water and fish will also escape with leaks and seepage. Proper lining is the best containment method to prevent all of these problems and more.
Permeability of Various Materials
Permeability is a major concern when it comes to containment. Without a proper, impermeable barrier somewhere in the construction of each pond or raceway, seepage and leaks are inevitable. Containing the water loss to a slow rate of seepage simply isn’t good enough for modern environmental protection regulations in most states. You’ll need to check the permeability of each material you use as a liner in your system to ensure at least one of them is as close to impermeable as possible.
Durability to Prevent Leaks and Losses
In addition to choosing a liner with impermeability, you’ll need one with durability. A thin and fragile liner will only tear over time due to the extremely high weight of thousands of gallons of water pressing down on it. Reinforced, multi-layer geomembranes are particularly well-suited to these kinds of aquaculture applications. The addition of a reinforcement layer prevents stretching in all directions and increases the liner’s tear resistance as well. In addition, the material will lay flat, speeding up installation by encouraging the material to spread smoothly with less work from the handling team. Trying to save money by buying an inexpensive liner will only result in extra costs for tear repairs over time.
Handling Wastewater
Recirculating aquaculture designs aim to minimize the loss of wastewater by running it through the system as much as possible. In an open system, with no pumps to recirculate the water with, waste is discharged onto the ground or into a body of water instead. Don’t plan to pipe wastewater directly from fish tanks or raceways into a natural release zone. Instead, plan extra ponds and processing areas to treat the wastewater until it’s safer to release. This will pay off by helping you avoid fines and the loss of discharge privileges, even if you’re relying on municipal sewage connections instead.
Pairing Tanks with Secondary Basins
Ponds and in-ground raceways are a better choice for most aquaculture designs than most above-ground tanks and containers. However, some tanks can’t be avoided when smaller volumes are needed for waste treatment and nutrient balancing containers. Any tanks you add to your system, for holding water at any point, deserves a secondary containment effort of a lined basin or holding pond. This ensures that if the tank suddenly bursts open or develops a serious leak, none of the water is really lost or expelled into the environment around the operation.
Take containment seriously for your aquaculture business or project to stay on the right side of federal and state environmental regulations. If you fail and have a few accidental discharges of fish wastewater, you might spend thousands of dollars in both fees and remedies to solve the problem. Prevent these leaks in the first place by using BTL Liners products for both primary and secondary containment. Our liners are durable enough to prevent leaks for years to come with only minimal maintenance on your part.
