^ Oil Tanker Exchanging Ballast Water – Image Courtesy of Igor Grochev at ShutterStock.com
Global Calamity in the Making
Transfer of aquatic invasive species is among the prime threats to the long term health of our oceans. And ballast water operations are the chief instrument of such transfers. These species leave their toxic imprint on the environment, economy, and public health.
More than a decade after the International Maritime Organization (IMO) first introduced the Ballast Water Management (BWM) Convention 2004, the convention remains a paper tiger for want of sufficient number of signatories.
Even if the convention does gather the required numbers and enters force, its execution will be far from a cakewalk infested as it is with the issues of multiplicity of norms, cost, and availability. Now, there is a fresh challenge of re-growth of microbes in treated ballast water.
Please note, that water covers about 71% of our planet’s surface. And oceans make up most of this water. Anything and everything that affects the well-being of oceans therefore should command paramount importance in the minds of all the stakeholders.
Ballast Water & the Transfer of Aquatic Invasive Species
Ballast water transfers are essential for the safety and stability of ships and crews. Seawater contains varied bacteria, virus, and the larval and adult stages of marine flora and fauna.
Most do not survive ballast water transfers. But those that do can ruin their destination areas. This is because these non-native ecosystems may not host the natural checks and balances that limit the populations of such species.
With absolutely no roadblocks, the populations of these non-native, invasive aquatic species expand to unsustainable levels and at the cost of native species. This creates dire repercussions:
Exotic species such as zebra mussels, hydrilla, Chinese mitten crab, New Zealand mudsnail and the like make merry in the absence of natural predators and destroy local ecosystems. This creates the need for checking their incursion.
By the early 1990s, the IMO had already spent a decade searching for solutions to the irksome issue of invasive species transfer. Prodded by Agenda 21 of the UN Conference on Environment and Development (UNCED) held in 1992 at Rio De Janerio, the IMO swung into action.
This culminated in the Ballast Water Management (BWM) Convention of 2004. As of April 19, 2016, 49 states representing 34.79% of the global merchant fleet tonnage have ratified the BWM Convention 2004.
It can enter force twelve months after 30 states representing 35% of the global merchant shipping tonnage sign it. Although the IMO had initially scheduled 2013 as the year for bringing the BWM convention into force, the convention is yet to see the light of the day.
After the BWM conventions enters force, all ships of 400 gt and above will need to install approved ballast water management systems (BWMS) when sailing in international waters. Exemptions include:
- naval auxiliary ships, state owned / operated ships, and warships
- ships not transferring or carrying ballast water
- ships not plying in international waters
- ships operating only for non-commercial reasons
Regulation D-2 of the BWM convention specifies the caps on organism concentration in ballast water. This is the same as the USCG-prescribed upper limits:
But even after the BWM convention comes into force, there remain the issues of:
- Diverse Requirements prescribed by the IMO and the United States Coast Guard (USCG)
- Cost of BWMS
- Re-growth of Microbes in Treated Ballast Water
- Availability of BWMS
Diverse Requirements & Availability: there exists a strategic divergence between the IMO and the USCG on this issue. IMO adheres to the G8 protocols for testing BWMS. These mandate testing in two salinity levels although ships ply through three such levels during global voyages.
Ships also need to comply with standards of individual states in the US as well as those laid down by the US Environment Protection Agency’s (USEPA’s) Vessel General Permit (VGP).
Instead, the USCG employs the Alternate Management System (AMS) – it allows ships fitted with a BWM convention-compliant BWMS that is certified by another flag state.
Now, the crux of the AMS is that it is a makeshift, five year arrangement. Ships with AMS-approved BWMS can ply and exchange ballast water in US waters for five years only. Such ships have to get full USCG type approval within these five years.
BWMS costs range from $50,000 to $5 million. Who will invest so huge a sum just for five years? BWMS makers have to invest $1-2 million and wait 18-24 months for testing a BWMS as per USCG standards. And shipowners have to wait for another 6-8 months to install it.
This and the twelve month interval for implementation after approval of the BWM convention will create an immense shortage. But BWMS makers cannot benefit because they do not know what to make.
Not only does it upset the calculations of BWMS makers but also the financials and scheduled dry dockings of shipping companies. Reliability and maximum uptime therefore become acutely important.
So ambiguous is the BWMS regulatory environment that last year editor of Maritime Reporter & Engineering News, Greg Trauthwein opined the state of affairs to be the most corrosive after the vicious debate on double hulled ocean tankers in the aftermath of the Exxon Valdez catastrophe.
Frost & Sullivan points to this uncertainty as a crucial issue for the shipping industry. And COO of GasLog Logistics, Graham Westgrath asserts that this is a result of regulators trying to impose laws way before technology was ready.
Cost: the Baltic and International Maritime Council (BIMCO) estimates the cost of installing a ballast water management system aboard a single ship at $5 million. If that sounds like exorbitant, wait till you hear the operational costs over the ship’s lifetime.
Costs for consumables, spares, and monitoring the systems to ensure they are working as expected add a fortune. Chemical costs can hit $0.08 per cubic meter of treated water and fuel costs will vary between $25 to $200 per year depending on the power requirement and flow rate.
Then there is the $2,000 per annum for miscellaneous maintenance. And the cost of replacing filter screens will range between $3,600 and $12,500. You need to change screens every five or ten years depending on the flow rate and the kind of water.
Market manager at Trojan Marinex, Mark Kustermans opines that annual operational expenses can vary from 3% to as much as more than 15% of the capital cost. This hits anywhere between $0.15 million and 0.75 million if we take the aforementioned $5 million as capital cost.
Again, the US Environment Protection Agency (EPA) prescribes dual monitoring for all systems that use active substances. The frequency of monitoring can be two to four times a year and adds to the cost vis-à-vis physical treatment methods.
Re-growth of Microbes in Treated Ballast Water: even after you go through this exhaustive grind, there are no cast iron guarantees on the elimination of invasive aquatic species. For, certain marine organisms grow even after you treat ballast water.
At the root of this is a contradiction. Many ships hold ballast water for over a week but the BWM convention calls for checking water held for a meager five days. And the corresponding USCG provisions call for testing water held only for one day. Here, IMO norms are stricter than USCG’s.
IMO Secretary-General Kitack Lim raised the issue at the Marine Environment Protection Committee (MEPC 69) meeting held in London between April 18 and 22, 2016 after equipment maker Coldharbor International brought it to his notice through a letter.
Ship operators stick to the generally accepted 10 parts per million (ppm) cap of sodium hypochlorite dosage. There are those who regard even this as excessive and call for a downward revision of 5 ppm.
Now, sodium hypochlorite loses its disinfection capabilities after a miserably low duration of three days, disintegrating and getting absorbed by seawater in this period.
Ozone treatment systems cannot give results if the mechanism fails to distribute ozone uniformly. Blessed with fine recovery mechanisms, microbes can re-grow after treatment. Testers have detected bacteria in ballast water two to seven days after ultraviolet (UV) treatment.
Although only a few microbes can survive chemical and UV treatment, these can cause sizable destruction. And these have a rich source of nutrition in the form of less resilient, dead microbes.
Technical Outline of Ballast Water Management Technologies
Ballast water treatment technologies borrow heavily from industrial and municipal wastewater treatment technologies. Two generic processes involved are:
- Solid-Liquid Separation: removes sediments, solids, and larger microbes via surface filtration or sedimentation
This stage may additionally employ Chemical Enhancement in the form of Flocculation or Coagulation
- Disinfection: is the second stage that eliminates or inactivates microbes using UV light (physical), chemicals, or suffocation
Chemical disinfection may use:
- Electro-chlorination / Electrolysis
The above two processes may add Residual Control via Chemical Reduction utilizing sulphites or bisulphites
- Chlorine dioxide
- Peracetic Acid
Additionally, chemical disinfection may add physical enhancement measures such as cavitation and ultrasonic treatment
Physical disinfection can be:
- UV Irradiation
- UV + TiO2
- Gas Injection
- Ultrasonic Treatment
- Pressure Vacuum Disinfection
Lloyd’s Register prescribes the following criteria for choosing a BWMS:
- type and operating profile of ship
- ballast capacity
- minimum and maximum ballasting and de-ballasting rates
- space the BWMS occupies
- degree of flexibility of the location of the BWMS elements
- BWMS’s level of compatibility with existing onboard mechanisms
- effect of BWMS on coatings and tank structures
- effect of pressure drop on the BWMS
- safety, health, and whether BWMS is certified as safe
- availability of power, spares, consumables, and support services
- additional crew training and workload the BWMS entails
- capital and operating expenditures
- BWMS delivery time and availability
Some of the available BWMS include:
- SeaCure by Evoqua
- RayClean by Desmi Ocean Guard
- EcoBallast and HiBallast by Hyundai Heavy Industries
- Ecochlor by Ecochlor Inc.
- Hyde GUARDIAN by Hyde Marine Inc.
- GLDTH by Coldharbor Marine
- Aquarius UV and Aquarius EC by Wartsila Water Systems Ltd.
- Optimarin Ballast System by Optimarin AS
In his quest to satisfy his insatiable appetite for economic growth and development, man has made deep incisions in the health of the environment.
The toll of such development is now assuming unsustainable proportions and we may soon hit the tipping point and slip into a downward spiral of ecological destruction.
Preventing this is a mammoth, but not an impossible task. Ensuring the execution of an effective ballast water management regime can be the first step in this epic marathon.
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