1.  MARINERS ARE HEREBY ADVISED that, this Notice to Mariners is to communicate Milford Haven Port Authority’s (MHPA) policy on the prohibition of discharge of exhaust gas scrubber wash water. This Notice applies to all vessels within the MHPA jurisdiction as set out in the Milford Haven Conservancy Act 1983 and subsequent legislation.


Habitats Directive (Directive 92/43/EEC), Water Framework Directive (Directive 2000/60/EC) & Environmental Quality Standards Directive (Directive 2008/105/EC).


       a. The Harbourmaster is responsible for maintaining and promulgating this policy to shipping via Notice to Mariners.
       b. Vessels Masters are responsible for complying with this policy.


       a. The recent tightening of the fuel Sulphur limits has promoted the use of exhaust gas scrubbers to reduce Sulphur emissions to air. While exhaust gas scrubbers reduce the atmospheric emissions of a number of pollutants, wash water discharges from scrubbers operated in certain modes may have significant environmental and ecological impacts. Of particular concern are the emissions of heavy metals, polyaromatic hydrocarbons (PAHs), nitrogen oxides (NOx), and the acidification of receiving waters and sediments.

       b. A number of these pollutants are identified as priority substances requiring the introduction of control measures to progressively reduce their discharge as set out in Article 16 of Directive 2000/60/EC (The Water Framework Directive), and for which environmental quality standards have been set in Directive 2008/105/EC (The Environmental Quality Standards Directive).

       c. The Welsh Government’s statutory advisor, Natural Resources Wales (NRW), has consulted with the Maritime and Coastguard Agency (MCA), and advises MHPA of MCA’s position that the options available to comply with the IMO 2020 Sulphur emissions cap in coastal waters are:

             i. Use ultra-low Sulphur fuel;
            ii. Use closed-loop exhaust gas scrubbing systems. By extension, the use of open-loop scrubbers is not considered to be a viable option in coastal waters.


       d. NRW has further considered the discharge of exhaust gas wash waters, and is of the opinion that this activity constitutes deposition of waste into the marine environment, an activity which, in all waters under NRW’s jurisdiction, would not be permissible under the terms of the Marine and Coastal Access Act 2009 (as amended), except after meeting the stringent requirements of marine licensing by NRW.  In determining any application for such a license, NRW would act as a Competent Authority under the terms of the Conservation of Habitats and Species Regulations 2017 (as amended) and as such would offer no guarantee that a license could in fact be issued.

       e. Currently there is no assessment of the long-term environmental impacts of the use of exhaust gas scrubbers. However, given the potential for impact on sensitive ecosystems, and the existence of Natura 2000 sites designated in accordance with the requirements of the Habitats Directive (Directive 92/43/EEC) (among other Marine Protected Areas, in the Milford Haven Waterway and its environs), MHPA must also fulfil its Competent Authority duties within its jurisdiction, and must exercise its statutory functions accordingly.  It is therefore MHPA’s policy that wash water from exhaust gas scrubber systems shall not be discharged to surface waters within its jurisdiction, unless the discharge is covered by a marine licence from NRW, as per paragraph 4c above. This is in keeping with the Precautionary Principle, as detailed in Article 191 of the Treaty on the Functioning of the European Union, aimed at ensuring a higher level of environmental protection through preventative decision‐taking in the case of risk.


Port of Milford Haven
Gorsewood Drive
Milford Haven
SA73 3EP

Tel: 01646 696100
Email: enquiries@mhpa.co.uk