Waste water without worries

With regulations getting tougher and pressure from environmental groups increasing it is inevitable that cruise ship owners will have to adopt new technologies in dealing with wastewater.

Conformance to IMO / USCG historic standards for treated sewage (black water) is not sufficient to meet the expectations of those responsible for regulating some coastal waters.

A heightened sensitivity to waste discharges has promoted monitoring of discharge water quality in such areas as Alaska and enforcement and penalties in the event of non-conformance to regulations is now the norm for this area.

Craig Vogt, from the US Environmental Protection Agency told delegates at the recent Seatrade Cruise Shipping conference in Miami that current Alaska black and grey water standards could be a precedent for national implementation. The EPA has proposed a separate voluntary programme directed at cruise ships called Blue Cruise to reduce air emissions and wastewater discharges.

Vogt highlighted some of the things that could be done, such as the use of biodegradable phosphate free soaps, low flow showers and toilets and the installation of grey water treatment systems that allows for reuse.

Taking things to an extreme could result in zero discharge of all waste. However, while there is likely to be no discharge of waste allowed in no discharge zones. Waste could be discharged at more than 10 knots at least three nautical miles from shore as studies have proven that this is less harmful to the environment.

Vogt says that marine sanitation device standards need updating. He explains that cruise ships are not stationary but ecosystems are and that dilution is not the solution. More than one million gallons (3,785 million litres) of grey water are typically produced on a 7-10 day cruise, which makes it the largest source of liquid waste generated by cruise ships. Multiply that by the number of cruise ships and it becomes a much bigger problem than many think.

Cruise lines and manufacturers are taking steps to try to reduce waste. QinetiQ in the UK has been carrying out trials on what it calls an Integrated Waste Management System (IWMS) ? see The Motor Ship, December 2002. Following the success of the IWMS trial, certain elements of the design are currently undergoing further evaluation towards a ship installation.

Dr Geoff Smith, a chemist at QinetiQ?s Environmental Sciences Dept says the modifications recently made to the submerged membrane bioreactor (black and grey water treatment) are being evaluated further on HMS Grafton, a naval vessel.

He explains that the bilge water separator is continuing its trials on HMS Richmond and that the company has just completed a feasibility study to consider the potential ship installation (two units) of the solid waste shredder, screw conveyor and cyclonic incinerator on to HMS Illustrious, another naval vessel, during its current refit and for HMS Ark Royal, yet another naval ship, during its next refit.

He says: “The IWMS study has helped to significantly de-risk any future ship installation and further trials will soon be conducted at QinetiQ with many of the IWMS recommendations included in to the new incinerator design. All of the trials of elements of the IWM system will help to significantly de-risk future ship installations and will provide greater confidence in the final integrated waste management system design if/when it becomes incorporated in its entirety at the design stage of any future RN ship.”

Hamworthy KSE is currently fitting the cruise ship Seven Seas Mariner with its new MBR (membrane bioreactor) system for black/grey water treatment. It is scheduled for completion by the end of this month (May), ensuring that the Seven Seas vessel destined to cruise in Alaska is fully compliant with the latest wastewater

regulations.

The company says that sea trials of the system have produced results that compare favourably with Alaskan regulations ? faecal coliforms averaging 10.6/100ml against the Alaskan requirement of 20/100ml, BOD less than 2.6mg/l against 30mg/l, and suspended solids 3.1mg/l against 30mg/l.

The first commercial system was installed on Seven Seas Navigator (see page 36) while in build at the Mariotti yard in Italy. Two MBR systems allow 10m3 of black water and 140m3 of grey water to be handled per day.

Orders have also been placed with Hamworthy KSE by the UK Navy to supply two MBR plants to its new Type 45 destroyer class. First delivery is scheduled for mid 2003.

An agreement between two companies, US-based Marine Environmental Partners, (MEP) and Italy?s ISIR, could see new wastewater treatment systems being developed that could benefit a wide range of vessels from cargo ships and cruise ships to offshore oil platforms. The companies claim that these new systems will meet and exceed new, more stringent environmental regulations, including the MARPOL Annex IV, slated to be enforced beginning in September 2003 and the regional regulations in Alaska and elsewhere already in place.

Jo Stewart, MEP?s vice-president of sales and marketing say: “The aim of the cooperation is to utilise the expertise and developed infrastructure of ISIR and the technological innovation of MEP in order to bring a process to commercialisation in the most expeditious possible manner. Needless to say there are many advantages to having access to EU based manufacturing as well as long established relations with the shipbuilding and ship repairing facilities that ISIR brings into the equation as well.”

MEP has developed its core MariSan electrochemical process for water and wastewater treatment independently. “We have also developed a treatment system for ship?s ballast that has been through lab testing over the last 21/2 years and shipboard pilot testing in 2002,” says Stewart. A permanent system is currently being installed on a California-based cruise ship. ISIR has specialized in the supply of wastewater treatment systems for decades. “They are key to the development of our shipboard wastewater treatment system and the components that allow for practical interface with existing systems and associated waste handling equipment,” explains Stewart. “In addition, with this combination of competencies, we can bring a managed project for a whole ship concept of waste handling from point of origin to final treatment and incineration, supplying all components with control over the design, manufacture and supply of nearly all major components and pre-engineered interface of systems to eliminate performance conflicts and to simplify service and warranty issues for newbuildings.”

The MEP MariSan treatment process is a modular component based process that allows adaptation to a number of shipboard water and wastewater treatment applications. MEP and ISIR will continue to develop systems to meet the needs of the marketplace beyond the grey and black water system now under way. The footprint of the MEP/ISIR by the nature of the process allows for a smaller footprint than traditional biological/membrane technologies now in use as grey and black water treatment systems

Stewart says that the wastewater pilot project is being done in conjunction with the SAFENVSHIP project in Genoa. The E-WWTP (Evolutionary Waste Water Treatment Plant) is expected to be completed and ready for testing under the programme guidelines in late May or early June with IMO & USCG type approvals and RINA certification complete in September. He explains: “The ballast system is commercially available today, and we are making proposals for systems to various ship owner/ operators at this time ? other applications are in the R&D stage.”