Table A4.9 Nitrogen eutrophication of surface water: control points, preventive — measures, target criteria and their verification Control points Preventive measures Target criteria Verification environments management authority. Soil Site selection minimised Nitrogen concentrations in In conjunction with appropriate nearby surface waters have experts, identify threats to surface not increased from baseline waters though recycled water use levels taken before on site-specific soils. development of the reuse scheme. Local waterways down slope of recycled water infrastructure and irrigation systems are buffered from Discharges to surface discharges, and runoff to waters minimised local waterways does not carry substantive nitrogen load. Soils Buffer distances and strips Verify that site Irrigation with recycled water management plan should not be conducted directly includes adjacent to surface waters. consideration of Appropriate buffer distances need diffuse and point to be observed and buffer plantings discharges to local used to strip nitrogen from runoff and regional surface (Appendix 6). waters, including consultation with relevant catchment Diffuse and point discharge of nitrogen to sensitive fertilisers, soils, etc), so excess Plants grow well in to inlet water and algal Irrigation and nutrients moving off-site are storage; nitrogen growth minimised. fertilisation limited. concentrations Nitrogen concentrations in decreased Crops and plants grown storage water decreased Incorporate plants that grow in the Nitrogen relative to inlet water and stored water, which strip nutrients concentrations algal growth minimised. from the recycled water. decreased to Storage acceptable levels system Shandy with fresh water No algae blooms. If nitrogen concentrations in stored water govern algae growth, shandy Algae number low with alternative water source to enough to prevent Storage decrease them. environmental issues system Light reduction Impacts of nitrogen on Restriction of recycled water to surface waters recognised in light sources will minimise algal Off-site impact from the management plan and growth (eg a sealed tank compared intentional or strategies for dealing with Storage with an open tank). unintentional intentional or unintentional system discharges minimised discharges developed in Management plan conjunction with local Site management plan should catchment management include consideration of off-site Crop nutrient authority. impacts of nitrogen from management plan Storage and intentional or unintentional in place and distribution discharges of recycled water on documented. Soil system nitrogen levels do local and regional surface water quality. not exceed plant Nutrient requirements. balancing Nutrients supply balance with Ensure crop demand from plants grown Nitrogen nutrient budget concentrations in includes inputs storage water from all sources decreased relative (water,
Table A4.9 Nitrogen — eutrophication of surface water: control points, preventive measures, target criteria and their verification Control points Preventive measures Target criteria Verification Soil Site selection In conjunction with appropriate experts, identify threats to surface waters though recycled water use on site-specific soils. Soils Buffer distances and strips Irrigation with recycled water should not be conducted directly adjacent to surface waters. Appropriate buffer distances need to be observed and buffer plantings used to strip nitrogen from runoff (Appendix 6). Diffuse and point discharge of nitrogen to sensitive environments minimised Discharges to surface waters minimised Verify that site management plan includes consideration of diffuse and point discharges to local and regional surface waters, including consultation with relevant catchment management authority. Nitrogen concentrations in nearby surface waters have not increased from baseline levels taken before development of the reuse scheme. Local waterways down slope of recycled water infrastructure and irrigation systems are buffered from discharges, and runoff to local waterways does not carry substantive nitrogen load. Irrigation and fertilisation Storage system Storage system Storage system Storage and distribution system Nutrient balancing Ensure crop nutrient budget includes inputs from all sources (water, fertilisers, soils, etc), so excess nutrients moving off-site are limited. Crops and plants grown Incorporate plants that grow in the stored water, which strip nutrients from the recycled water. Shandy with fresh water If nitrogen concentrations in stored water govern algae growth, shandy with alternative water source to decrease them. Light reduction Restriction of recycled water to light sources will minimise algal growth (eg a sealed tank compared with an open tank). Management plan Site management plan should include consideration of off-site impacts of nitrogen from intentional or unintentional discharges of recycled water on local and regional surface water quality. Nutrients supply balance with demand from plants grown Plants grow well in storage; nitrogen concentrations decreased Nitrogen concentrations decreased to acceptable levels Algae number low enough to prevent environmental issues Off-site impact from intentional or unintentional discharges minimised Crop nutrient management plan in place and documented. Soil nitrogen levels do not exceed plant requirements. Nitrogen concentrations in storage water decreased relative to inlet water and algal growth minimised. Nitrogen concentrations in storage water decreased relative to inlet water and algal growth minimised. No algae blooms. Impacts of nitrogen on surface waters recognised in the management plan and strategies for dealing with intentional or unintentional discharges developed in conjunction with local catchment management authority.
water-recycling-guidelines-full-21.docx