Wastewater discharge, whether from ships, septic tanks, sewage systems, or agriculture, significantly impacts marine ecosystems. With the growing nautical sector in the Mediterranean, there is increasing concern about the harmful effects of wastewater discharge from vessels.
What exactly is wastewater and how does it affect the sea?
Wastewater often contains various pollutants, including heavy metals and pathogenic microorganisms. Wastewater generated on vessels can be divided into bilge water and sanitary wastewater.
- Bilge water falls under the category of industrial wastewater and is created by collecting water with a high oil content from engine rooms and boilers, including a mixture of oil, seawater, fuel sediments, and chemicals used for degreasing and cleaning.
- Sanitary wastewater is further divided into black and grey wastewater:
- Black wastewater refers to sewage, including discharges from toilets, medical rooms, and spaces housing live animals. The black wastewater produced on ships is different from that on land due to shorter retention times and lower water content, as a result of reduced water usage for flushing sanitary facilities.
- Grey wastewater refers to water used for cleaning in domestic and living areas, such as wastewater from sinks, showers, bathtubs, laundries, and food preparation areas, as well as from dishwashers and spaces where food is stored or served.
The harmful impact of pollutants in wastewater on marine water quality depends on the discharge volume, chemical composition, and concentration of these waters. Marine pollution can lead to changes in nutrient levels, the number and diversity of organisms, the accumulation of organic and inorganic compounds, and alterations in the food chain.
The impact of black wastewater is relatively small compared to that of grey water, which can cause serious ecological problems. The presence of difficult-to-degrade organic pollutants in grey water can lead to the degradation of phytoplankton communities and the accumulation of these substances in plants and animals, potentially causing harmful effects on human health, especially on the endocrine system.
We also address the issue of wastewater in the Adriatic Sea as part of the EFFICIENTN2K project. Learn about our project activities so far here.
Croatia has a legally mandated ban on wastewater discharge from vessels into the sea
Croatia is a signatory to the International Convention for the Prevention of Pollution from Ships (MARPOL 73/78 Convention), which prohibits the discharge of wastewater from ships into the sea. In national legislation, the Maritime Code was amended in 2013 to include a ban on wastewater discharge from vessels into the sea and an obligation to empty these tanks only at designated locations (in or outside the port) where appropriate reception facilities are available.
The Maritime Code thus prohibits the discharge and disposal of all substances that pollute the sea into the sea or onto the coast. Regarding subordinate regulations, one set specifies the conditions for ports, requiring them to be equipped with the appropriate facilities for separate waste collection (Regulations on the conditions and methods of maintaining order in ports and other parts of internal waters and territorial sea of the Republic of Croatia), while another set specifies the conditions for vessels, mandating the installation of tanks (Regulations on boats, crafts, and yachts).
Additionally, concessionaires of nautical anchorages are required to collect municipal waste from vessels at anchor. The Maritime Domain and Sea Ports Act (NN 83/2023, Article 145, Paragraph 4) stipulates that the concessionaire of a nautical anchorage is responsible for safety and order at the anchorage and must accept municipal waste from vessels, and may provide other services to sailors in accordance with the concession agreement and the Maritime Domain and Sea Ports Act.
Barriers to law enforcement: significant changes are needed at the national level
Although current regulations prohibit the discharge of wastewater from vessels into the sea and prescribe conditions for ports and vessels, in practice, the real situation does not fully comply with the regulations. Some media outlets have already addressed this issue (portal Gorgonija.com, 2020., portal Otvoreno more), noting that the deadline for installing black tanks was the end of 2021, by which time the construction of the entire accompanying infrastructure on land was expected. However, there still aren’t enough stations on land, nor is there a sufficient system of controls and penalties. Even if all marinas were equipped with these stations, it still wouldn’t be enough. Not all yachts and boats are in marinas, and in marinas that are tourist-oriented (charter bases), a large number of vessels return within just a few hours (usually on Fridays and Saturdays), which means that such marinas should be equipped with a large number of stations.
Therefore, other solutions should be considered (e.g., building a network in other places where vessels dock). According to an article on Otvoreno more, it was determined that the ports open to international traffic (Pula, Rijeka, Zadar, Šibenik, Split, Ploče, and Dubrovnik) have ensured the acceptance of all reference types of waste through subcontractors, while this is still not the case for smaller ports. Regarding conditions for vessels, today, almost all new boats and yachts have black tanks installed, but they still lack grey tanks. Boats and yachts without serious modifications do not have the space to install grey tanks.
Report wastewater discharges and be part of the change!
Monitoring wastewater discharge from ships is crucial for preserving the marine environment and maintaining the attractiveness of these areas for visitors. The maritime safety inspection is carried out by 17 maritime safety inspectors stationed in the Maritime Safety Directorate and port authorities, along with 105 authorized personnel stationed in port authorities (MMPI, 2024).
On average, about 67 cases of marine pollution are recorded annually, but only a small portion of these are related to pollution from vessels (as opposed to land-based or unknown sources). Clearly, there is a need to improve the monitoring of pollution caused by ships and the methods for determining the exact source of pollution so that those responsible can be financially penalized. Sunce advocates for this as part of its online summer campaign on sustainable practices at sea, aimed at sailors and all sea lovers, And where do you anchor?.
But we are not alone in advocating to strengthen control in the Adriatic; all citizens are involved! By reporting to the Green Phone – a free tool provided by Sunce that offers information and advice to citizens and helps resolve environmental issues in local communities – you can become an active driver of positive change!
If you notice marine pollution, don’t hesitate to call us at 072 123 456 or send an email to [email protected]. You can do so anonymously, and our legal team will strive to prompt the authorities to take action and resolve the case as quickly as possible. You will be promptly informed of all actions taken.
The Green Phone network exists at the national level, and Sunce automatically receives calls from the Split-Dalmatia and Dubrovnik-Neretva counties.
We’re waiting for your call!
https://gorgonija.com/2020/11/23/crni-tankovi/
https://more.slobodnadalmacija.hr/om/nautika/nauticari-i-dalje-zagaduju-uvale-zabrana-ispustanja-fekalnih-voda-s-plovila-zapela-zbog-prihvatnih-stanica-1294212
