Appendix P - Irrigation Water Quality Guidelines Appendix P Irrigation Water Quality Guidelines This appendix provides guidelines for irrigation water quality.It draws heavily on the Australian Water Quality Guidelines for Fresh and Marine Waters,published in November 1992 by the Australian and New Zealand Environmental and Conservation Council. For a more detailed account and explanation of the rationale behind the levels set out in this appendix, readers are referred to Section 5.1 (Irrigation) ofChapter 5 (Agricultural Water Uses) of the above publication. Table P1 - Summary of Guidelines for Irrigation Water Quality Parameter Guideline Comment (mg/L, unless otherwise stated) Chloride 30-700 (Tables P2, P3, Maximum concentration should P4) be set according to sensitivity of crop Sodium Crops Table P5 Total dissolved solids Tables P6, P7 Heavy Metals and Trace Irons* Aluminium 5.0 High toxicity in acid soils Arsenic 0.1 Beryllium 0.1 Boron 0.5-6.0 Table P8 Cadmium 0.01 Higher toxicity in acid soils Chromium 1.0 Limit chromium (VI) concentration to 0.1 mg/L. Cobalt 0.05 Copper 0.2 Fluoride 1.0 Iron 1.0 Lead 0.2 Lithium 2.5 Citrus 0.075 mg/L Manganese 2.0 If acid soils, limit to 0.2 mg/L. Mercury 0.002 Molybdenum 0.01 Nickel 0.2 pH (CaCl)2 4.5-9.0 Selenium 0.02 App P - 1