Frequently asked questions about ballast water treatment and the Trojan Marinex BWT system.

Consult the most frequently asked questions below.

Ballast Water FAQs

What is ballast water?

Ballast water is used to stabilize vessels and ensure structural integrity. It is typically pumped in while cargo is being unloaded, and discharged while cargo is being loaded. Safety, weather conditions, a ship's load, and the route taken are the primary factors that determine how much ballast water is taken on board a vessel. More ballast is necessary for ships to sit lower in the water during stormy weather.  Ballast water is also used to balance the ship as it uses up fuel during a long voyage.

What is ballast water treatment?

Ballast water treatment is the process of treating ballast water in order to actively remove, kill and/or inactivate organisms prior to discharge. Ballast water treatment is different from the older process of ballast water exchange, which involved completely flushing the ballast water tanks during voyages.

Water taken on in one ecological zone and released into another can result in the introduction and spread of aquatic invasive and nuisance species – this is a serious threat to our environment.

Why is ballast water treatment important and needed?

Ballast water taken on in one ecological zone and released into another introduces aquatic invasive and nuisance species that may have detrimental impacts on the biodiversity, economy or human health of the receiving community.

What regulations are guiding ballast water treatment?

IMO: The International Maritime Organization (IMO) launched the Ballast Water Management Convention (also known as the International Convention for the Control and Management of Ships’ Ballast Water and Sediments) in 2004. It will enter into force on September 8, 2017. The convention states that ballast water must be treated – to specific standards – before it’s released back to the environment.

United States: Vessels sailing in U.S. waters will be required to adhere with United States Coast Guard (USCG) ballast water discharge standards and the United States Environmental Protection Agency (USEPA) Vessel General Permit (VGP), in addition to State ballast water regulations.

The USCG’s final rule establishes a ballast water discharge standard which is the same as that adopted by the IMO in 2004. In addition, the USEPA 2013 Vessel General Permit has adopted numeric limitations within the permit that also align with the USCG rule. The USCG final rule will affect all vessels – U.S. and foreign – that operate in U.S. waters, are bound for ports or places in the U.S., and are equipped with ballast tanks.

What is included in the certification and Type Approval process?

Technologies developed for ballast water treatment are subject to approval through specific processes and testing guidelines designed to ensure that such technologies meet the relevant standards. The approval consists of both land-based testing of a production model to confirm that the discharge standards are met, and shipboard testing to confirm that the system works in service.

The most relevant Guidelines are the IMO G8 Guidelines “GUIDELINES FOR APPROVAL OF BALLAST WATER MANAGEMENT SYSTEMS (G8)”. These guidelines are issued by the International Maritime Organization and outline an evaluation procedure (including land- and ship-based testing) that equipment will undergo to demonstrate that they meet the ballast water discharge standards set out in the Ballast Water Convention.

In addition, systems that are issued US Coast Guard Type Approval must undergo testing according to the “Environmental Technology Verification (ETV) Generic Protocol for the Verification of Ballast Water Treatment Technology”. The ETV protocol is similar to the G8 guidelines as it contains evaluation procedures  for system testing, however, it is much more prescriptive in nature. Its objective is to evaluate the performance characteristics of commercial-ready treatment technologies with regard to specific verification factors, including biological treatment performance, predictability/reliability, cost, environmental acceptability, and safety.

Trojan Marinex FAQs

Do you have channel partners?

Yes, forming mutually-beneficial, strategic partnerships is an important part of our ballast water treatment business. You can learn more about our worldwide partner network here.

Is the system IMO Type Approved?

Yes. In March 2014 the Trojan Marinex BWT product suite obtained International Maritime Organization (IMO) Type Approval from Det Norske Veritas (DNV) on behalf of the Norwegian Maritime Directorate.

Does the system have USCG Alternate Management System (AMS) acceptance?

Yes. In August 2014 the Trojan Marinex BWT product suite received USCG AMS acceptance - in accordance with the USCG’s final rule for Standards for Living Organisms in Ships’ Ballast Water Discharged in U.S. waters - for all water qualities: freshwater, brackish water and marine water.

Does it meet USCG discharge standards?

We performed our IMO certification process to the rigorous standards required by the USCG, supporting our goal of achieving USCG Type Approval. Testing was conducted under the supervision of DNV - who is now certified as an Independent Lab (IL) by the USCG - in accordance with USEPA ETV Ballast Water Protocol.

Have you submitted an application for USCG Type Approval?

Yes, in March 2015 a formal application for USCG Type Approval was submitted – this was the first application in the industry.

Do you have active substance (G9) approval for the system?

The two primary guidelines exist for the approval of BWT systems are G8 and G9. The Trojan Marinex BWT system will obtain Type Approval from DNV on behalf of the Norwegian Administration. The Norwegian administration has determined that our system only requires G8 approval because it does not employ an active substance.

The G8 guidelines broadly specify approval of drawings, land-based and shipboard tests, and environmental tests. The G8 guidelines apply to all BWT systems, whereas, the G9 guidelines specify guidelines for systems that employ an active substance or chemical. The primary objective of G9 is to determine the impact of the active substance on the marine environment. Systems that employ an active substance are required to undergo both G8 and G9 approval. Systems that do not employ an active substance are only required to obtain G8 approval.

Some UV-based systems require G9 approval because they employ a slightly different process called advanced oxidation. In this process, UV light is emitted onto a titanium dioxide plate to create a hydroxyl radical (OH). The hydroxyl radical is considered an active substance, thus requiring G9 approval. In contrast, the Trojan Marinex BWT system employs state-of-the-art UV specifically designed for marine applications. In this process, ballast water is treated with UV light which does not cause a chemical change in the water.

How does the system work?

During ballasting, water receives dual treatment – filtration and UV. Filtration removes larger particles and organisms. UV inactivates the remaining organisms and microorganisms. During deballasting, water bypasses filtration and is treated with UV only. The primary reason that the filter is bypassed during deballasting is to avoid having to discharge the filter backwash effluent into the deballasting location.

Why are the two treatment processes integrated into one unit?

Synergistic effects are created by integrating filtration and UV within one unit. Water flows through the filter directly to the UV chamber. Flow rate is consistent, pressure drop is minimal, and no additional pipes or pumps are needed. The filter acts as a flow modifier resulting in lower velocity and more evenly distributed flow coming out of the filter, leading to more stable and ideal conditions for UV.

Why did you custom-design your own filter?

We spent a number of years bench- and full-scale testing a multitude of off-the-shelf options, identifying the specific impacts (positive and negative) each had on system performance, operation and reliability. Understanding every aspect – including construction, types, weave patterns and sizing – was absolutely essential. We rigorously tested numerous filter media and constructions, including wedge wire and an extensive array of mesh options.

By identifying the inadequacies of off-the-shelf filters, while refining and perfecting specific key features, we proceeded to custom-design and construct our own filtration system – one that would work in perfect unison our TrojanUV Solo Lamp™ Technology. It provides the ideal balance of high performance and reliable run times.

Is the system explosion-proof?

An explosion-proof version of each Trojan Marinex BWT system is available for vessels where installation in a potentially explosive environment is required. Each are certified in accordance with ATEX directive and IECEx scheme, carry a T4 temperature class rating and are applicable for installation in zone 1 hazardous areas.

What are the power requirements?

Power requirements for the system will vary according to the ballast water flow rate. For example, a 500 m3/h system requires 24 kW. Extensive research and development has been undertaken to reduce overall power requirements.

What are the space requirements?

A compact unit – that can fit easily into a pump or engine room – is a must. Ours are up to 50% smaller than others in the industry. On certain models, the inlet and outlet flanges are removable to allow the unit to be easily maneuvered aboard the vessel.

How does the filter backwash work?

To prevent clogging, the backwash sequences occurs automatically during ballasting. Individual filter elements are isolated and flow is reversed through them – this removes any debris that may have collected on the element. The cleanliness of each element is detected, and backpressure is adjusted accordingly. A large waste stream drain pipe returns backwash water to the point of origin.

How are the UV lamps cleaned?

UV lamps are housed within quartz sleeves. Over time, without proper cleaning, sleeves can become fouled. Quartz sleeve fouling is very problematic because it reduces the amount of UV energy transmitted to achieve treatment.

Our automatic, chemical-free cleaning system uses wipers plates to remove fouling, without disrupting operation. This technology is derived from various products developed by Trojan Technologies companies. It has been proven and utilized for over two decades, throughout some of the most challenging water treatment applications, including primary treated wastewater.

What maintenance is required and what is the time estimate for maintenance?

The system has been specifically designed to minimize and simplify maintenance requirements. Components (such as UV lamps, drivers and filter elements) are all easily accessed from a central location, and can be maintained by any crew member. No extensive training or water treatment expertise is required.