2016-02-02 P&O Committee - Item 3 - Attachment 4 - Mary River Environmental Values and Water Quality Objectives

            Mary River environmental values and water quality objectives




            3 Water quality objectives (WQOs) to protect environmental
              values
            This section provides water quality objectives (WQOs) to support and protect different environmental values
            identified for waters within the Mary River catchment in Table 1.

            This section is in two main parts:
            • Section 3.1 (Table 2) outlines WQOs to protect the aquatic ecosystem EV. The aquatic ecosystem EV is
                a default applying to all waters, and therefore the WQOs for aquatic ecosystems form the minimum
                WQOs for all waters. Where no human use EVs are identified, the WQOs identified for aquatic
                ecosystem protection remain applicable; and

            •    Section 3.2 (Tables 3 to 12) provides WQOs for EVs other than aquatic ecosystem (‘human use EVs’)
                 such as recreational water use, irrigating crops, and aquaculture.

            Sources used in deriving WQOs are provided after the tables.

            Reference to the identified EVs in Table 1 of this document provides guidance on the EVs applying to waters
            within the catchment. Where reference to Table 1 indicates more than one EV applies to a given water (for
            example aquatic ecosystem and recreational use), the most stringent WQO for each water quality indicator
            applies, which will then protect all identified EVs. Refer to the two following examples on selection of most
            stringent WQOs. Note that these are examples only and should not be directly adopted for use.


            Example 1:

            For lowland freshwater streams with aquatic ecosystem and drinking water EVs, the respective turbidity
            WQOs are:
            • aquatic ecosystem lowland freshwater stream: <50 NTU; and
            • drinking water: <25 NTU.

            In this case the drinking water WQO (<25 NTU) is the more stringent, and its adoption therefore supports
            both the aquatic ecosystem and drinking water EVs.

            Example 2:

            In the following situation there are stock watering and irrigation EVs, with differing WQOs for thermotolerant
            (faecal) coliforms (measured as median number of organisms per 100 mL):
            • stock watering: <100 organisms per 100 mL;
            • raw human food crops in direct contact with irrigation water: <10 organisms per 100 mL; and
            • pasture and fodder for dairy animals: <100 organisms per 100 mL

            The most stringent WQO is that for direct irrigation of raw human food crops (<10 organisms per 100 mL)
            and its adoption would in turn provide faecal coliform WQOs that protect all the above-identified human use
            EVs.




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Document Set ID: 20002123
Version: 1, Version Date: 21/12/2015