What is Ballast Water?
Ballasts are essential for cargo ships. If you’ve ever watched a dramatic submarine movie, you may have heard sailors shouting about the ballasts. In submarines, ballast tanks control the depth that the vessel operates at. The same is true for cargo ships and other large vessels. Ships regularly take in and expel water. This process can have wide ranging environmental impacts, which is why the shipping industry has started to adopt ballast water monitoring.
Taking on and expelling water provides stability and helps assure safe operation of the ship. A ship carrying no cargo or less than full capacity will often take on water to weigh the ship down. This makes it easier to control. Once cargo is loaded up, the water is then expelled.
So what is ballast water? It’s the water that is taken into a cargo ship’s ballast water tank. Unfortunately, ballast water is often plagued by bacteria, other microbes, and aquatic organisms, such as mussels. If ships fill their ballasts in one region, say South East Asia, and then dispel the water in another region, perhaps of the coast of California, there is a high risk that the local environment will be contaminated.
The threats posed by ballast water are not hypothetical. They are very real, and in some cases have come to fruition. Zebra mussels from Eastern Europe, for example, now plague the Great Lakes in the United States. These mussels have caused irreparable harm to local ecosystems.
International Ballast Water Regulations Increasing
As a result of the very real threats posed by ballast water, many authorities are now pushing ballast water regulations. The United Nations International Maritime Organization (IMO) has been increasing oversight in an effort to protect global ecosystems and waterways. Under IMO oversight, shipping companies can expect to face heightened ballast water management standards.
In fact, the Ballast Water Management Convention now provides global oversight for discharges and other issues. Now, all international traffic is required to engage in ballast water management and to meet ballast water treatment standards. All ships flagged the signatories must meet monitoring and treatment standards.
Under the IMO’s Ballast Water Management treaty, ships must control and treat both water and sediments. Ballast water treatment eliminates harmful organisms and invasive species. This prevents the spread of invasive plants, animals, and bacteria through ballast water discharge.
The United States is not a signatory of the IMO agreement. However, the American Coast Guard has implemented its own ballast water regulations and requires the treatment of ballast water before discharge to American waters. Individual states and especially those bordering the Great Lakes, have also installed various laws regarding ballast water discharges and related issues.
Ballast Water Monitoring Supports Effective Ballast Water Treatment
As a result of the risks posed by ballast water, many shipping companies have begun to monitor their ballast water tanks. Many governments have also implemented ballast water regulations. Ballast water monitoring is becoming essential for meeting regulatory requirements and protecting the environment. Every shipping company should have a ballast water management plan in place.
The first step to a ballast management plan is to understand the risks. The next step is to assess whether risks are present. This means ballast water testing. Then, if necessary, it is important to utilize ballast water treatment technology to mitigate or eliminate risks. Let’s see what this actually looks like.
UV Ballast Water Treatment
UV disinfection is one viable method of ballast water treatment, with an increasing number of ships equipped with UV ballast water treatment systems. These systems can kill many of the organisms and microbes present in ballast water. To ensure that UV ballast water treatment is effective, shipping companies can monitor UV transmittance. UVT is an indicator of the organic content in water and is therefore useful for verifying that bacteria, including pathogens, have been destroyed.
Another parameter of interest in ballast water monitoring is pH. The pH of ballast water determines the kinds of organisms that are able to survive in the ship’s ballast tank. Understanding the pH levels in ballast water can help ship operators create an effective ballast water treatment plan.
Other methods of ballast water treatment for ships are being explored as well. What’s certain is that contamination levels and the effectiveness of ballast water treatment technologies will have to be closely monitored. If not, local ecosystems could be exposed to considerable risks.
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