2 Definitions
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Resolutions - Marine Environment Protection Committee - Resolution MEPC.227(64) – 2012 Guidelines on Implementation of Effluent Standards and Performance Tests for Sewage Treatment Plants – (Adopted on 5 October 2012) - Annex - 2012 Guidelines on Implementation of Effluent Standards and Performance Tests for Sewage Treatment Plants - 2 Definitions

2 Definitions

  2.1 Annex IV – the revised Annex IV of the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the 1978 and 1997 Protocols (MARPOL), as amended by resolutions MEPC.115(51), MEPC.200(62) MEPC.216(63), MEPC.246(66), MEPC.265(68) and MEPC.274(69).

  2.2 Convention – the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the 1978 and 1997 Protocols (MARPOL).

  2.3 Dilution (Qd) – is dilution water, grey water, process water, and/or seawater introduced to the sewage treatment plant after the influent sample point and after the influent flow measurement device, see figure 1.

  2.4 Effluent (Qe) – treated wastewater produced by the sewage treatment plant, see figure 1.

  2.5 Flush water – transport medium used to carry sewage or other wastes from toilets or urinals to the treatment system.

  2.6 Geometric mean – the nth root of the product of n numbers.

  2.7 Grey water – is drainage from dishwater, galley sink, shower, laundry, bath and washbasin drains and does not include drainage from toilets, urinals, hospitals, and animal spaces, as defined in regulation 1.3 of MARPOL Annex IV and does not include drainage from cargo spaces.

  2.8 Hydraulic loading – system design flow rate of waste water (Qi) into the sewage treatment plant.

  2.9 Influent (Qi) – Liquid containing sewage, grey water or other liquid streams, to be processed by the treatment plant, see figure 1.

  2.10 Sample point – A point for manual collection of a representative sample of influent and effluent without opening tanks, voids or vents, see figure 1.

  2.11 Testing on board – testing, for the purpose of type approval, carried out on a sewage treatment plant installed on a ship.

  2.12 Testing ashore – testing ashore, for the purpose of type approval, carried out on a sewage treatment plant.

  2.13 Thermotolerant coliforms – the group of coliform bacteria which produce gas from lactose in 48 hours at 44.5°C. These organisms are sometimes referred to as "faecal coliforms"; however, the term "thermotolerant coliforms" is now accepted as more appropriate, since not all of these organisms are of faecal origin.


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