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Indicator 2.7.2

Requirement

The UoC shall not discharge brackish or saltwater effluent over land.

Evidence of Implementation

  • The location and/or route of the discharge of brackish or saltwater effluent to demonstrate discharge does not take place over land.

  • Examples of evidence may include maps/plans of the discharge locations/routes.

Auditors Should Confirm

  • Evidence has been presented, such as maps/plans, to demonstrate brackish or saltwater effluent is not discharged over land.

Indicator 2.7.1

Requirement

Indicator applicability: brackish or saltwater pond culture The UoC shall3838An exemption applies where ponds are located in naturally brackish or saline environments. use low permeable liners.

How Do I Interpret This Requirement?

  • Brackish water has a salinity of 0.5-29.9 ppt, while seawater has a salinity of > 29.9 ppt.

  • Low permeable liners include liners made from:

    • Plastic,

    • Imported clays,

    • Ripping and re-compaction of in situ clays, mixing with bentonite,

    • Geo-membranes, and

    • Composite liners.

Evidence of Implementation

  • Records demonstrating the installation and maintenance of low permeable liners in ponds.

Auditors Should Confirm

  • Low permeable liners have been installed and maintained in ponds.

Indicator 2.6.22

Requirement

Indicator scope: point source systems in waterbody types A and B The UoC shall conduct DO monitoring downstream from the outflow point and shall demonstrate that daily diurnal DO (DDDO) fluctuation is ≤65% saturation, following the method outlined in Appendix 8 (8.11).

How Do I Interpret This Requirement?

  • For UoCs located in tidal systems, timing of measurements should correspond with high and low tides, to reflect variations related to the tidal regime.

  • The UoC can conduct DO monitoring immediately downstream of the last site in a waterbody whilst still following the sampling method in Appendix 8 (8.11).

  • This may reduce sampling costs when there are multiple sites discharging point source effluent releases to a Type B waterbody near each other.

  • The methods outlined in Appendix (8.11.2 and 8.11.3) shall be used to record DO concentrations used to determine daily diurnal DO (DDDO).

  • Any missed samples or deviations in sampling time should be accompanied by a written justification.

Evidence of Implementation

  • Records that DO measurements correspond to high and low tides in tidal systems.

  • The location of the sampling point, demonstrating that measurements have taken place downstream from the outflow point.

  • Results of daily DO monitoring and DDDO fluctuation calculations.

Auditors Should Confirm

  • DO measurements have taken place at high and low tides in tidal systems.

  • DO measurements have taken place downstream from the outflow point.

  • The UoC has presented results of the DDDO calculations based on DO measurements collected in accordance with the methods outlined in Appendix 8.11.1 and 8.11.2.

  • Confirm the fluctuation level based on the DDDO calculation is ≤65% saturation level.

  • Written justifications were provided if there were any missed samples or deviations in the sampling time.

Indicator 2.6.16

Requirement

The UoC shall use a treatment system prior to the discharge of effluent water that ensures: – ≥65% of Total Suspended Solids (TSS) are captured; and, – concentration of settleable solids in effluent water is <3.3ml/L.

How Do I Interpret This Requirement?

  • Methods to measure Total Suspended Solids (TSS) can be found in Appendix 8 (8.12).

  • Concentration of settleable solids (ml/L) can be measured by calculating the volume of solids that settles to the bottom of a conical cone (Imhoff cone) in one hour.

  • More sophisticated methods such as spectrophotometer readings can also be used to measure settable solids.

Evidence of Implementation

  • Details and location of the system used to treat effluent prior to discharge.

  • Evidence regular testing of TSS and settleable solids has taken place. Quarterly testing would demonstrate best practice.

  • Results from the testing of point source releases which demonstrate ≥65% of TSS are captured and the concentration of settleable solids in effluent water is consistently <3.3ml/L.

Auditors Should Confirm

  • A treatment is in place and located prior to the point of discharge.

  • Results of testing from the UoC which confirm the treatment system captures ≥65% of suspended solids and that the concentration of settleable solids in effluent water is <3.3ml/L.

Indicator 2.6.10

Requirement

The UoC shall, after the determination of the water quality baseline, conduct monitoring of the water quality parameters listed below, following the method outlined in Appendix 8 (8.8):3434An exemption applies if the mean of Secchi Disk (SD) depth calculated over any rolling two-year period remains ≥10m. – Total Nitrogen (TN); and, – Total Phosphorous (TP); and, – Dissolved Oxygen (DO); and, – Secchi Disk (SD) depth; and, – Chlorophyll-a (Chl-a).

How Do I Interpret This Requirement?

  • Quarterly monitoring ensures the UoC can capture any seasonal or inter-annual variations in the data collected.

  • Measurements should be timed to coincide with, or immediately follow, annual turnover events when the waterbody is not permanently stratified (holomictic).

  • The UoC should calibrate equipment used to measure DO, TN, TP, SD and Chl-a according to the technical specifications of the equipment.

  • The UoC should conduct measurements of the parameters in-situ.

  • Samples may be sent for laboratory analysis, however variability with sample maintenance during transit can lead to inconsistent results. This is particularly evident with DO and Chl-a samples.

Evidence of Implementation

  • Documentation outlining the sampling plan to conduct quarterly monitoring and that is in accordance with Appendix 8 (8.8).

  • Quarterly monitoring data has been collected and submitted to the ASC Water Quality Calculator. Data should be submitted at least annually.

  • Evidence that quarterly monitoring data has been timed with annual turnover events (where applicable).

  • That equipment to measure DO, TN, TP, SD and Chl-a has been calibrated according to technical specifications.

Auditors Should Confirm

  • The sampling methodology to conduct quarterly monitoring is in accordance with Appendix 8 (8.8).

  • The UoC has conducted quarterly monitoring of the water quality parameters and submitted data to the ASC Water Quality Calculator at least annually.

  • Evidence has been provided demonstrating the UoC has calibrated equipment to measure DO, TN, TP, SD and Chl-a in accordance with the technical specifications.

Useful Resources

  • Paerl, H.W., Scott, J.T., McCarthy, M.J., Newell, S.E., Gardner, W.S., Havens, K.E., Hoffman, D.K., Wilhelm, S.W. and Wurtsbaugh, W.A., 2016. It takes two to tango: when and where dual nutrient (N & P) reductions are needed to protect lakes and downstream ecosystems. Environmental science & technology, 50(20), pp.10805-10813.

  • Information on the appropriate use of Secchi Disks can be found here: ‘What is a Secchi disk’, accessed November 22, 2023: <https://www.nalms.org/secchidipin/monitoring-methods/the-secchi-disk/what-is-a-secchi-disk/>

  • Example of a method for Chl-a measurements made using ethanol extraction followed by spectrophotometric measurement at wavelengths 665 and 750nm (using accredited methods: EPA method 445.0: Method 445.0 In Vitro Determination of Chlorophyll a and Pheophytin ain Marine and Freshwater Algae by Fluorescence, accessed November 22, 2023: https://cfpub.epa.gov/si/si_public_record_report.cfm?Lab=NERL&dirEntryId=309417

  • Cost effective example for measuring using in-situ Chl-a using a field spectroflurometer include the FluoroSense handheld fluorometer manufactured by Turner Designs and the YSI handheld meter with EXO1 (#599080) or EXO2 (#599201) sondes.

  • Hamdhani, H., Eppehimer, D.E., Walker, D. and Bogan, M.T. (2021) Performance of a Handheld Chlorophyll-a Fluorometer: Potential Use for Rapid Algae Monitoring. Water, 13, 1409: https://doi.org/10.3390/w13101409

  • Kuha, J., Järvinen, M., Salmi, P. and Karjalainen, J. (2020). Calibration of in situ chlorophyll fluorometers for organic matter. Restoration of Eutrophic Lakes, 847, 4377-4387: <https://doi.org/10.1007/s10750-019-04086-z>

Indicator 2.6.9

Requirement

The UoC shall conduct a water quality survey and determine the water quality baseline, including the trophic status, following the method outlined in Appendix 8 (8.8).

How Do I Interpret This Requirement?

  • The data collected as part of the 24-month site level monitoring survey is submitted by the UoC to the ASC Water Quality Calculator.

  • The water quality baseline is based on 24-months of monitoring data from the site level monitoring survey. However, the following phased approach is permitted when sites do not have sufficient data prior to the initial audit:

    • The water quality baseline is characterised by the ASC Water Quality Calculator, in accordance with Appendix 8 (8.8).

    • The baseline should be conducted per site and per waterbody. The results should then be shared with members of the WQMN.

    • The baseline determines whether primary production in the waterbody is limited by nitrogen (N), phosphorous (P), or if it is co-limited. Other factors (than N or P) may be limiting primary productivity in a waterbody.

    • The UoC should present evidence of these other limiting factors (e.g. temperature or altitude) where applicable.

  • Harmful algal blooms (HABs) and Adverse Turnover Events (ATEs) are required to be reported as part of the baseline characterisation. The number of ATEs and HABs that have occurred can be recorded by conducting the following:

    • Reviewing news media and consulting local stakeholders. Alternatively, reviewing data collected by regulatory bodies where available.

    • Reporting the number of ATEs and HABs which have resulted in fish mortality events (farmed or wild) or the mortality of other aquatic species.

    • Reporting instances where fish mortality events or loss of other aquatic species can be attributed to natural phenomena. These instances will not count towards the frequency limits for ATEs and HABs.

    • Reporting the number of ATEs and HABs, as determined by national or regional regulatory/scientific organisations.

Evidence of Implementation

  • The methodology and analytical methods used to conduct site level monitoring survey are in accordance with Appendix 8 (8.8).

  • The sampling methodology for collecting 24-months of data for the site level monitoring survey, if this is not available at the initial audit.

  • The results of the site level monitoring survey, as determined by the ASC Water Quality Calculator.

  • The results of the 24-month baseline characterisation, as determined by the ASC Water Quality Calculator.

  • Records of HABs and ATEs from the last 10 years.

Auditors Should Confirm

  • A water quality monitoring survey has been conducted by the UoC. Results are presented from the ASC Water Quality Calculator.

  • A sampling methodology has been presented for collecting 24-months of data for the site level monitoring survey, if this is not available at the initial audit.

  • The data collected for the site level monitoring survey followed the methodology and analytical measures outlined in Appendix 8 (8.8).

  • A water quality baseline has been characterised. Results are presented from the ASC Water Quality Calculator.

  • The results of the review by the UoC into adverse turnover events and harmful algal blooms in the waterbody.

Useful Resources

  • Vollenweider, R.A., Rinaldi, A. and Montanari, G. (1992) Eutrophication, structure and dynamics of a marine coastal system: results of ten-year monitoring along the Emilia-Romagna Coast (Northwest Adriatic Sea). Marine Coastal Eutrophication, Proceedings of an International Conference, Bologna, Italy, 21–24 March 1990, Pages 63-106: <https://doi.org/10.1016/B978-0-444-89990-3.50014-6>

  • More information about the equations used for TSI assessment, including the relevant peer-reviewed scientific literature, is provided in Carlson, R.E. and Simpson, J. (1996) A Coordinator’s Guide to Volunteer Lake Monitoring Methods. North American Lake Management Society, 96 p.

Indicator 2.6.8

Requirement

The UoC shall establish a Water Quality Monitoring Network (WQMN), following the method outlined in Appendix 8 (8.7). An exception applies where a WQMN is already established, in which case the UoC shall participate in the WQMN.

How Do I Interpret This Requirement?

  • Evidence of spatial management at a national/regional level for water quality can be used by the UoC to demonstrate that the intent of Indicator 2.6.8 has been met. To use this evidence, the following should be met:

    • The boundaries of waterbodies are defined.

      • Waterbodies are managed to ensure water quality remains at a ‘Good’ or ‘Very Good’ status.

      • Where required, corrective actions are implemented by the regulator and complied with to ensure water quality status improves.

    • Examples of spatial management at a national/regional level include the European Union Water Framework Directive.

    • It is the responsibility of the UoC to conduct outreach to ASC Certified sites and non-certified sites belong to ASC Certificate Holders if a Water Quality Monitoring Network (WQMN) has not been established.

  • Examples of outreach can include:

    • Copies of correspondence (written and email).

    • Agendas and minutes of meetings.

    • Third-party stakeholder testimony.

  • As per Appendix 8, section 8.7, a Terms of Reference (ToR) document shall be drafted and agreed upon by all members of the WQMN upon formation, which includes the following:

    • The membership list and commitments from members to meet the WQMN requirements, as outlined in Appendix 8 (8.7.1).

    • The assignment of a focal point, who will coordinate data sharing, the drafting of the ToR and agreement to the ToR by all members of the WQMN.

    • The focal point should ideally be a rotating position, though determination is left to discretion of the WQMN membership.

    • A commitment to review the ToR on a regular basis (for example every 12 months) or as and when required, such as when changes in membership of the WQMN occur, or when the waterbody demonstrates evidence of excessive nutrient loading, eutrophication or trophic status shifts.

Evidence of Implementation

  • An agreed map of the WUM by members of the WQMN, which includes the components outlined in Appendix 8 (8.7).

  • The map should be updated on an annual basis where required.

  • Evidence of outreach efforts and responses (where applicable) to ASC Certified site and non-certified sites belong to ASC Certificate Holders if a WQMN needs to be established.

  • If a WQMN has been established, the UoC presents evidence that they have joined the WQMN or the UoC can demonstrate the spatial management of water quality at a national/regional level.

  • A ToR has been agreed upon by all members of the WQMN, which includes commitments to the WQMN requirements, as outlined in Appendix 8 (8.7.1).

Auditors Should Confirm

  • A map of the WUM has been developed by the WQMN and presented by the UoC, which includes the components outlined in Appendix 8 (8.7).

  • Evidence of outreach efforts and responses to ASC Certified site and non-certified sites belong to ASC Certificate Holders if a WQMN needs to be established.

  • Auditor discretion should be used to determine if sufficient levels of outreach has been conducted, when such outreach has not been reciprocated.

  • Evidence that the UoC has formed/joined a WQMN, or that the UoC presents evidence that water quality is managed at a national/regional level.

  • A ToR has been presented, which has been agreed upon by all members of the WQMN. The ToR includes commitments to the WQMN requirements, as outlined in Appendix 8 (8.7.1).

Indicator 2.6.7

Requirement

The UoC shall ensure that the person conducting water quality monitoring has the necessary competencies, experience and training. The UoC shall ensure that the person defining the WUM has the necessary competencies. In cases where regulatory requirements are defined, the UoC shall ensure that the person defining the WUM complies with these requirements.

How Do I Interpret This Requirement?

  • To demonstrate competence, personnel responsible for conducting water quality analysis and defining the WUM should be able to:

    • Perform the required sampling and/or analysis.

    • Operate sampling/analytical equipment.

      • Develop, change, verify and validate methods.

    • Use suitable reference standards.

    • Analyse sampling and calibration results, including statements of conformity and interpretations.

      • Record, review and authorise the release of results.

    • Contribute to or produce reports that can clearly and concisely explain whether the results meet the requirements.

      • Have completed relevant training modules.

Evidence of Implementation

  • The personnel responsible for conducting water quality analysis and defining the WUM have competencies to do so, for example a suitable level of education and/or experience.

    • Where applicable, the personnel meet national requirements/qualifications for the spatial definition and/or management of waterbodies.

  • Relevant training modules have been completed by the personnel responsible for conducting water quality analysis and defining the WUM.

Auditors Should Confirm

  • The personnel responsible for conducting water quality analysis and defining the WUM have the necessary competencies.

    • Where applicable, national requirements/qualifications are met by the personnel defining the WUM.

  • Evidence has been presented that relevant training modules have been completed.

Indicator 2.6.6

Requirement

The UoC shall define the Waterbody Unit of Management (WUM), following the method outlined in Appendix 8 (8.6). An exception applies where a WUM is already defined, in which case the UoC shall provide evidence of the defined WUM.

How Do I Interpret This Requirement?

  • The following characteristics should be used to define the Waterbody Unit of Management (WUM):

    • The WUM reflects a logical geographic scope, for example, a lake and its catchment area.

    • The boundaries of the waterbody reflect the ability to realistically manage eutrophication risk within it.

    • Boundary setting should consider hydro-morphology, bathymetry, water movement and stratification characteristics.

      • Areas with high risk of adverse impacts due to cumulative effects, for example HIEs in larger waterbodies, should be a separate WUM.

      • Areas established for water quality monitoring at a national or regional level.

    • The Water Quality Advisory Committee (WQAC) can resolve issues with defining the WUM where the WUM boundaries are not clear.

Evidence of Implementation

  • A map of the WUM which includes the components outlined in Appendix 8 (8.6).

    • The map should be updated on an annual basis where required.

  • The results of measurements to confirm if the WUM is a HIE (if applicable).

Auditors Should Confirm

  • A map of the WUM has been developed and presented by the UoC, according to the method outlined in Appendix 8 (8.6).

Indicator 2.6.5

Requirement

The UoC shall ensure that the Receiving Waterbody (RW) has been classified per site as Type A, B or C, following the method outlined in Appendix 8 (8.5).

How Do I Interpret This Requirement?

  • The UoC should initially define the boundaries of the Receiving Waterbody (RW) based on hydrological characteristics, which determines its sensitivity to nutrient enrichment.

    • Hydrodynamically isolated embayments (HIEs) should be treated as separate waterbodies during the classification process.

  • Marine waterbodies include:

    • Off-shore and inshore coastal systems.

    • More enclosed waterbodies susceptible to seawater intrusion through tidal exchange or storm surges.

    • Exposed near-shore waterbodies (i.e. not in a bay or channelised system) and offshore waterbodies will be classified as Type C.

    • Once the boundaries of the RW are defined, HRT should be calculated unless the RW is an exposed near-shore or offshore waterbody.

      • The area and average depth of the waterbody need to be determined.

    • The cross-sectional area of the waterbody outflow or channel is required to calculate flow rate.

    • A transect should be determined from one side of the outflow/channel to the other side.

      • The length (in metres) of the transect is multiplied by the average depth of the transect to determine the cross-sectional area.

      • The cross-sectional area in then multiplied by the flow velocity (V). The result of this calculation is the flow rate (Q).

      • If a marine waterbody has HRT ≥5 days, it is a Type A, if it is ≤ 5 days, it is Type C.

    • Determining flow rate and levels of Total Suspended Solids (TSS) will distinguish between Type B and C freshwater bodies.

    • Flow rate can be obtained from regulatory bodies. Low flow then needs to be calculated by plotting the cumulative distribution of the data and calculating the 25^th^ percentile of the cumulative distribution.

    • This can be calculated in Microsoft Excel using the cumulative distribution function. The 25^th^ percentile (or quartile) can then be calculated.

  • Waterbody types designated under national legislation should be used only if the following are met:

    • The classification includes area-based water quality monitoring.

      • Targets are used to determine good ecological status. An example is the Water Framework Directive.

Evidence of Implementation

  • A map of the Receiving Waterbody, which outlines:

    • The area and average depth of the waterbody; and,

      • The location where flow rate (Q) was determined; or,

    • That the site is in a RW which is an exposed near-shore or off-shore marine RW (Type C only).

    • The waterbody classification, which includes outputs from HRT, flow rate and TSS calculations.

      • The methods used to measure flow rate and TSS, in accordance with Appendix 8 (8.5 and 8.12).

      • If applicable, evidence that demonstrates alternative methodologies to calculate TSS or flow rate are equivalent to the ones in Appendix 8 (8.5).

Auditors Should Confirm

  • A map has been presented by the UoC which outlines the RW, and which supports the classification of the RW.

  • The results of the HRT calculation and flow rate/TSS measurements conducted by the UoC.

    • These results will support the RW classification determined by the UoC.

  • Evidence presented by the UoC, demonstrating the methods used to measure flow rate and TSS, in accordance with Appendix 8 (8.5 and 8.12).

Useful Resources

[Steps to determine whether the RW is a HIE are as follows:]

1. If the site is in a waterbody that has been identified as a HIE by a regulatory body, this will form the boundaries of the RW.

2. Review the characteristics of the RW and determine if at least one of the following is identified:

  • The RW has poor connectivity to deep offshore waters, and/or;

  • The RW is sheltered from energetic conditions e.g., inflows, currents, exposure to onshore or monsoonal winds, and/or;

  • The hypolimnion is periodically or permanently poorly flushed.

> Where the RW shares these characteristics, it is possible to demonstrate the RW is not a HIE. The steps to demonstrate that the RW is not a HIE are as follows:

1. Identify the narrowest point in the embayment opening (red line in Figure 1).

2. Establish two transects of length, which start at the narrowest point and extend in and out of the embayment (red dashed line in Figure 1).

3. Collect water samples at 0.5m depth from an equal number of equally spaces sites in each transect.

4. Analyse water samples for concentrations of chloride, conductivity, salinity, TN or TP. Analytical methods for TN and TP can be found in Appendix 8 (8.12).

5. Plot the concentrations of the parameter analysed in step 4 against their position on the transects.

6. Based on the results from step 5, determine whether there is a statistically significant increasing or decreasing trend in concentrations moving from the furthest offshore to the most enclosed site.

7. An embayment is hydrologically isolated when a statistically significant increasing or decreasing trend in concentrations has been determined.

Figure 1. Tracer sampling points along a transect for HIE determination.