Pacific Maritime Magazine - Marine Business for the Operations Sector

Small Vessel Ballast Water Treatment


March 1, 2020

Glosten's oneTank Ballast Water Treatment system is a very small, low power system suitable for a small vessel operator. Photo courtesy of Glosten.

The small vessel operator that must install a Ballast Water treatment system has little choice other than a handful of 'compact' versions of systems developed for large ocean going ships. One exception is the oneTank system developed by naval architecture and marine consulting firm, Glosten specifically for small vessels applications.

With locations in Seattle and Providence, Glosten has considerable experience refitting marine vessels with Ballast Water treatment systems (BWT). While working with an industry partner on an in-tank BWT system, the Glosten team recognized the need for a very small, low power system suitable for a small vessel operator.

The oneTank system fits in a small 2-foot by 2-foot footprint, which is about 25 percent smaller than the smallest competing "compact" system. The power requirements meet what is available on small marine vessels, a single 15-amp supply at either 120 or 230 volts single phase. System installation and commissioning has been designed to be "do-it-yourself" by the vessel operator. This approach is in response to vessel operator desires to reduce or eliminate engineering costs, class society technical review fees, and the risk of cost overruns and schedule delays in Shipyard. Installation steps include:

• Install a new pipe from the existing ballast pump discharge to the unit,

• Mount the 400-pound 2-foot by 2-foot unit,

• Install a new pipe, valve, and bulkhead penetration to each Ballast Water tank,

• Install mixing nozzles in each of the Ballast Water tanks, using CPVC piping, and

• Run single 15 amp cable to the unit.

Operation is designed to be simple and fully automatic. The system mixes bleach into the Ballast Water tank, ensures a minimum 24-hour hold time, and then neutralizes any remaining bleach with a liquid sulfite. The ballast pump circulates Ballast Water from the ballast tank, through oneTank, and then back into the Ballast Water tank through the mixing nozzles.

Treatment can be conducted at the operator's convenience, allowing him to avoid treatment during busy in-port times. One gallon of household bleach will treat a 9,000-gallon Ballast Water tank. There is no filter, therefore no filter maintenance, and the system automatically adjusts chemical dose to account for varying water quality. oneTank measures the bleach concentration, adds bleach or sulfite as needed, and informs the operator when the tank is "ready for discharge."

Tankship Aftpeak Tanks

The resulting oneTank system has found a surprising application in the aftpeak tank on tankships. The many large forebody Ballast Water tanks on a tankship are the primary focus of a tankship's treatment system installation, requiring extensive effort and attention. The Ballast Water in these tanks must be handled as gas-hazardous as the tanks are adjacent to the cargo tanks. The aftpeak tank, on the other hand, is almost always an afterthought. It is usually smaller than the cargo body tanks, by regulation is completely isolated from forebody ballast system, and most importantly is just one tank. As a result, a complete BWT system is typically installed to treat this single, isolated Ballast Water tank.

The Glosten-developed system is a very good fit for these isolated aftpeak tanks, offering a compact, easy to install, easy to operate system. This can reduce cost and time spent on the aftpeak and allow the integration team to focus on the more complex forebody treatment system. The system is expected to receive US and international type approval in the near future.

Does My Small Vessel Need to Treat Its Ballast Water?

Are you small enough? If your vessel is less than or equal to 1,600 gross registered tons or alternatively less than or equal to 3,000 gross tons per the International Convention on Tonnage Measurement of Ships, 1969, it is exempt from the Ballast Water management requirements in 33 CFR 151.2025 as long as it does not operate outside of the US or Canadian EEZ.

What about yachts? The US Coast Guard management requirements in 33 CFR 151.2025 and EPA's Vessel General Permit do not apply to recreational vessels. This means that these requirements would not apply to recreational yachts – even very large ones. However, if those yachts are used for commercial purposes, such as on charters, then the requirements would apply.

How about limited operating areas? Vessels that operate exclusively within the boundary line, ("non-seagoing," see 46 CFR part 7), are exempt from Ballast Water management requirements in 33 CFR 151.2025. Vessels that operate exclusively within one Captain of the Port (COTP) Zone, or that only take up and discharge Ballast Water with one COTP Zone are also exempt. Also exempt are vessels that do not travel more than 10 nautical miles and don't cross a physical barrier such as a lock, regardless of if they operate in more than one COTP Zone.

The Vessel Incidental Discharge Act (VIDA) was passed in 2018 and has the potential to change the US Ballast Water regulations. VIDA repealed the EPA Small Vessel General Permit and amended the Clean Water Act by establishing "Uniform National Standards for Discharges Incidental to Normal Operation of Vessels." The EPA is required by December 2020 to develop new federal standards for performance of marine pollution control devices such as BWT systems, and within the following two years US Coast Guard must develop implementing regulations. It is not expected that VIDA will affect the above noted exemptions.

Although such exempted vessels do not have to perform Ballast Water management, most are still required to comply with certain reduction practices, reporting, and recordkeeping in 33 CFR 151.2050, 151.2060, 151.2070 and the VGP equivalents.

The small vessels that do have to perform Ballast Water management include:

• Commercial vessels of any size that discharge Ballast Water in US waters after operating outside of the US/Canada EEA,

• Commercial vessels of more than 1,600 Gross Domestic Tons that uptake and discharge Ballast Water in more than one COTP Zone, and

• All vessels of any size that discharge Ballast Water in foreign ports in compliance with international requirements.

Kevin Reynolds, a graduate of the US Merchant Marine Academy, has led Glosten's marine environmental engineering efforts for more than a decade, including pursuit of solutions for Ballast Water management in accordance with sound environmental practice.

UV-Based Ballast Water Treatment

In the 15 years since the protracted wrangling of the IMO Ballast Water Management Convention began, many companies that initially entered the market have faltered or folded, overwhelmed by business expense, procurement problems and an indecisive regulatory process. In 2015, more than 100 OEMs were in the running; today, fewer than 20 seem like plausible candidates.

Among these "remainers" is the French UV-based Ballast Water treatment system manufacturer, BIO-UV Group.

"Many manufacturers roll out a new version of their system that fits with the latest regulation," explains Benoît Gillmann, BIO-UV Group founder and CEO. "Most recent are the new IMO G8 guidelines, which are considerably more stringent than those we had from IMO previously."

Gillmann says his company didn't need to make any changes to their design to meet the new regulations. The system has been exhaustively tested in water of all salinities and turbidities. "When testing the system, we did not use the best water from the best places," Gillmann explains. "We did our shipboard testing all over the world: Rotterdam, China, USA, Australia, the UK, India and Singapore."

The BIO-SEA system consists of a modular UV reactor., which features only one bulb, protected inside a transparent quartz sleeve, and the assembly is sealed inside a watertight titanium and copper-alloy body.

Operating in two separate modes, each reactor can handle a throughput of 150m3/h while running in IMO mode – using the MPN method to render the microorganisms inert – or 100m3/h in US Coastguard CMFDA ("kill") mode.

The required flow rate dictates the number of reactors in each installation, with new reactors added in increments of 150m3/h: a 1,000m3/h system would comprise only seven reactors with only one UV lamp in each one.

The main point of failure for any UV Ballast Water treatment system is the lamp, which just as with any other bulb, requires replacing on a relatively predictable schedule. Because of murky or brackish water, each lamp, no matter how powerful, can only be used within a certain circumference of water flow around it.

Because BIO-SEA system uses only one lamp per reactor, there is one easily-remedied point of failure. The design features a long UV chamber with a narrow diameter, allowing for high water flows and maximum UV coverage per cubic meter of water. The company says this approach keeps maintenance and operating costs consistent compared with other systems, such as electrochlorination.

BIO-SEA has struck deals with a number of major players, recently outfitting CMA CGM Opera Series vessels with 1,000m3/h capacity installations.

"CMA CGM wanted to have the full flow capacity for US Coastguard compliance," explains Xavier Deval, BIO-SEA business director. "These vessels have two ballast pumps working on full flow through the system. With pre-engineering done and the components waiting at the drydock, the installation was done inside of two weeks."

As the BWTS installation dates deadlines loom, BIO-UV Group reports that the retrofit market is making up an increasing percentage of its business.

Kevin Reynolds, a graduate of the US Merchant Marine Academy, has led Glosten’s marine environmental engineering efforts for more than a decade, including pursuit of solutions for Ballast Water management in accordance with sound environmental practice.

The printed version of this story that appeared in the March issue of Pacific Maritime Magazine had inaccurate regulatory requirements. The EPA regulations called out in this online version are correct.


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