Alannah Duffy – Environmental Advisor · Report Title | Burgess Creek Receiving Environment Monitoring Program Annual Assessment and Review 2022 | Project | Burgess Creek Monitoring Program | Project Summary Annual review of environmental monitoring undertaken in accordance with the Burgess Creek | Monitoring Program for Noosa Sewage Treatment Plant releases into Burgess Creek for 2021. | Document Review | Document | Document | Author | Reviewed By | Approved By | Version | Status | Alannah Duffy | Scott Lowe | A7541556 | Final | Michael Robinson | Environmental Advisor | Environmental Advisor | Environment Team Leader | Issue Approval | Destination | Object ID | Completion Date | Unitywater - Objective | A7541556 | 3 May 2023 | Contents | 1.0 | Executive Summary .................................................................................................. 1 | 2.0 | Scope ......................................................................................................................... 1 | 2.1 | Report Structure and Contents ................................................................................. 2 | 3.0 | Monitoring Area for the Burgess Creek Monitoring Program ................................ 3 | 3.1 | Environmental Values Water Quality Objectives ....................................................... 4 | 3.2 | Guidelines for Fresh and Marine Water Quality ........................................................ 5 | 3.3 | Noosa STP treated wastewater release conditions .................................................. 6 | 4.0 | Burgess Creek Monitoring Program ........................................................................ 7 | 5.0 | Results ..................................................................................................................... 10 | 5.1 | Climatic Conditions ................................................................................................ 11 | 5.2 | Summary Statistics ................................................................................................ 13 | 5.3 | Spatial Trends ........................................................................................................ 13 | 5.4 | Temporal Variability ............................................................................................... 23 | 5.5 | Long term variability ............................................................................................... 33 | 5.6 | Statistical Comparison of 2020 and 2021 Monitoring Data ..................................... 41 | 5.7 | Compliance of 2021 data with Water Quality Objectives ........................................ 43 | 5.8 | Comparison with Recreational Water Quality Limits ............................................... 44 | 5.9 | Compliance of treated wastewater releases with Environmental Authority | EPPR008691113 ............................................................................................................. 45 | 6.0 | Discussion ............................................................................................................... 47 | 7.0 | Recommendations .................................................................................................. 55 | 8.0 | References ............................................................................................................... 56 | 9.0 | Appendices .............................................................................................................. 58 | Appendix A - Summary statistics of nutrient concentrations and microbiological | indicators at each monitoring site ................................................................................... 58 | 1.0 Executive Summary | Unitywater undertakes surface water monitoring in accordance with the conditions present | within the Environmental Authority EPPR008691113 (the EA) for Noosa Sewage Treatment | Plant (STP) in the Burgess Creek Catchment. This annual report summarises the surface | water monitoring conducted throughout the 2021 calendar year. During the 2021 review | period, 0 non-compliances were recorded for treated wastewater releases from the Noosa | STP in association with the conditions imposed by the EA. | Water quality monitoring data collected as part of this program has been presented in nine | ways to ensure that the influence of the treated wastewater discharged from the Noosa STP | is adequately represented and assessed. Results highlighted the complexity of the Burgess | Creek catchment and the potential influence of the STP along with additional land use, ocean | proximity and groundwater input drivers. Changing climatic conditions, statistically significant | differences, and temporal variability sourced from estimated flow rate defines trending results | with decreased water in the Catchment. A comparative assessment with Water Quality | Objectives (WQO) indicated a consistent trend of overall compliance with the water quality | objectives. | 2.0 Scope | The Burgess Creek Monitoring Program has been developed to ensure compliance with the | EA. Its purpose is to assess the potential impacts of the Noosa STP treated wastewater outfall | within the Burgess Creek catchment. The program is designed per conditions NHW5 and | NHW6 of the EA outlined in Figure 1. It addresses physical, chemical and biological water | quality indicators in line with environmental values of lowland freshwaters in the Noosa River. | Figure 1. Condition NHW5 and NHW6 of Environmental Authority EPPR008691113 (p40). | This document may not, in whole or part, be copied, photocopied, reproduced or translated | without prior consent from the CEO, Unitywater. | The purpose of this Burgess Creek Monitoring Program Annual Assessment and Review is to | conduct an annual evaluation, explanation or assessment of the monitoring data collected by | this Receiving Environmental Monitoring Program (REMP). This assessment report completes | the requirement in condition G13 of the EA outlined in Figure 2. | Figure 2. Condition G13 of Environmental Authority EPPR008691113 (p8). | 2.1 Report Structure and Contents | The annual report has been prepared to meet the EA and REMP reporting | requirements and includes a summary of the following: | • | Presentation of data collected during the 2021 calendar year; | • | Comparison of 2021 data to the most appropriate water quality and biological | objectives; | • | Graphical comparison of 2021 data with historical data; and | • | Statistical comparison of 2021 data to historical data. | Monitoring data collected from the Burgess Creek Monitoring Program have been | presented in nine ways to ensure that the influence of the treated wastewater | discharged from the Noosa STP is adequately represented and assessed: | 1. An assessment of climatic conditions contributing to the water quality of | Burgess Creek | 2. A table summary of the monitoring data collected; | 3. Scatter plots with standard error bars graphically presenting spatial trends | within Burgess Creek; | 4. Line plots graphically presenting temporal trends (monthly) at each monitoring | site; | This document may not, in whole or part, be copied, photocopied, reproduced or translated | without prior consent from the CEO, Unitywater. | 5. Scatter plots with trend lines demonstrating long-term trends at each monitoring | site; | 6. Students' t-tests provide statistical comparisons between current and previous | years' monitoring data; | 7. Tabled comparison of data against water quality objectives and a line graph | demonstrating historical compliance trends. | 8. A table of percentage compliance with recreational water quality limits for | microbiological indicators; and | 9. A table summary of percentage compliance of treated wastewater releases with | the EA. | 3.0 Monitoring Area for the Burgess Creek Monitoring Program | The Burgess Creek catchment covers an approximate area of 5.6 km2 in the Noosa Shire | Council region of Queensland. Two branches of the Creek, the East and West, join to form | the main Burgess Creek. Burgess Creek flows in a general south-easterly direction before | discharging into the Pacific Ocean at Sunrise Beach. It is a small catchment situated between: | • | Coastal sand dunes created by wind and wave action to the east; | • | Noosa River to the north; and | • | Weyba Creek and Lake Weyba to the west and south. | While the Burgess Creek catchment is small, the complex interaction of existing and past land | uses resulted in the Catchment being considered moderately disturbed. The predominant land | use is remnant vegetation and urban. Residential dominates in the elevated parts of the | Catchment and natural vegetation within the lower regions, particularly within the floodplain | and immediately around Burgess Creek. | Burgess Creek discharges from a partly urbanised catchment through an area of | environmental value onto a beach widely used for recreation. The Creek is subject to varied | land uses, which are inclusive of but not limited to the following: | • | Noosa STP; | • | Two de-commissioned landfills; | • | Noosa National Park and Conservation Parks | • | Girraween Sporting Complex; | • | Girraween State High School; and | • | Recreational activities on Sunrise and Castaway Beaches. | A detailed review of the land-uses present within the Burgess Creek catchment is within the | report prepared by KBR (2004) and its implications on the Burgess Creek water quality. | This document may not, in whole or part, be copied, photocopied, reproduced or translated | without prior consent from the CEO, Unitywater. | The water types in the Burgess Creek Catchment are based on the Australian and New | Zealand Guidelines for Fresh and Marine Water Quality (2000) and mapping and definitional | rules contained in the Queensland Water Quality Guidelines (QWQG) (Department of | Environment and Heritage Protection (DEHP), 2009). It is classified as lowland freshwater, | divided into a wallum/tannin-stained freshwater subtype in southeast Queensland. The | wallum/tannin-stained freshwaters can be defined as tannin-stained, generally low gradient, | small to mid-sized streams, many with sandy substrates and low pH, tea-coloured water | draining through wallum vegetation. It is derived from work for the Ecosystem Health | Monitoring Program (Department of Environment and Science (DES), 2015). | 3.1 | Environmental Values Water Quality Objectives | The QWQG defines Environmental Values (EVs) for water as the qualities of water that | make it suitable for supporting aquatic ecosystems and human water uses. These EVs | need to be protected by maintaining and/or enhancing the water quality from the effects of | habitat alteration, wastewater releases, runoff, and changed flows to ensure healthy | aquatic ecosystems and waterways that meet community use and expectations. For | management purposes, waters are grouped into catchments and sub-catchments, and EVs | are provided at a catchment level to protect defined water uses. | In 2019 the Department of Environment and Science began reviewing its EVs and WQOs | throughout Queensland. As part of this process a number of changes have been made to | mapping, environmental values and water quality objectives for Burgess Creek. The new | document which prescribes new environmental values and water quality objectives for | Burgess Creek is titled “Noosa River environmental values and water quality objectives”. | The revised EVs and WQOs were published in July 2022. Upon review it has been noted | that there have been extensive changes made and new mapping that needs to be | integrated into future assessments. This review has determined that there is a disconnect | between the ecological value mapping in Burgess Creek and the prescribed environmental | values and water quality objectives. Due to the number of changes and noted discrepancy | between two key documents, it is recommended that DES is engaged to discuss the | application of WQOs within future assessments. Once resolved, it is recommended for | inclusion in the Burgess Creek Monitoring Program Annual Review for 2023. | The document titled "Environmental Protection (Water) Policy 2009 Noosa River | Environmental Values and Water Quality Objectives" has been retained and used in this, | the 2021 Review to compare the environmental values and water quality objectives for the | This document may not, in whole or part, be copied, photocopied, reproduced or translated | without prior consent from the CEO, Unitywater. | monitoring year 2021 within Burgess Creek. The environmental values applied within this | assessment are listed in Table 1 (Department of Environment and Sciences (DES), 2010). | Table 1. Environmental values applicable to Burgess Creek. | Water | Environmental Value | Other | estuarine | Aquatic Ecosystem | tributaries | Human consumer | Primary recreation | Secondary recreation | Visual recreation | Cultural and Spiritual value | Spiritual value | The Water Quality Objectives (WQOs) used for comparison within this assessment are | those listed under Area NF1 for "Lowland Freshwater – Aquatic Ecosystem Moderately | Disturbed". Table 2 lists the water quality objectives that have been applied to the | monitoring area of the Burgess Creek REMP for this monitoring period. | Table 2. Water quality objectives most applicable to Burgess Creek. | Water Quality Parameter | Unit | Limit | Suspended Solids | mg/L | <6 | Chlorophyll a | μg/L | <5 | Total Nitrogen | μg/L | <500 | Ammonia N | μg/L | <20 | Total Phosphorus | μg/L | <50 | Filterable Reactive Phosphorus | μg/L | <20 | Dissolved Oxygen | % saturation | 85-110 | pH | H+ | 6.5-8.0 | Conductivity | μS/cm3 | 500 | 3.2 | Guidelines for Fresh and Marine Water Quality | The Australian and New Zealand Environmental Conservation Council (ANZECC) and | Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000) define | the limits for primary and secondary recreational use for microbiological indicators to | ensure public health. These guidelines provide the limits for thermotolerant coliforms and | This document may not, in whole or part, be copied, photocopied, reproduced or translated | without prior consent from the CEO, Unitywater. | enterococci. The guidelines also discuss the primary recreational limit set in New Zealand | for E.coli, but this value has not been adopted in Australia within these guidelines nor in | other guidelines published. No secondary recreational limits for E.coli have been | prescribed or published in New Zealand. The primary and secondary limits prescribed | within the ANZECC (2000) Australian and New Zealand Guidelines for Fresh and Marine | Water Quality are in Table 3. | Table 3. Primary and Secondary Recreational Contact Guideline Values | Microbiological Indicator | Units | Primary | Secondary | Recreational | Recreational | Guideline Limit | Guideline Limit | Enterococci | cfu/100mL | 35 | 230 | Thermotolerant coliforms | cfu/100mL | 150 | 1000 | E.coli | cfu/100mL | 1260 | NA | 3.3 | Noosa STP treated wastewater release conditions | The Noosa STP is authorised to release treated wastewater in accordance with conditions | NHW2, and NHW3 within the EA outlined in Figure 3. | Figure 3. Condition NHW2 and NHW3 of Environmental Authority EPPR008691113 (p40). | These release limits stipulate the minimum quality of the treated wastewater that can be | released from the prescribed release points. An extract of key release limits for treated | wastewater at Noosa STP from Schedule 2, Table 26 from the EA is in Table 4 and Table | 5. | Table 4. Mass Load limits at the Noosa STP | Average Annual | Nitrogen 50th | Nitrogen | Phosphorus | Phosphorous | Flow (ML/year) | Percentile | (Kg/year) | 50th Percentile | (mg/L) | (mg/L) | (Kg/year) | 5110 | 5 | 25 550 | 1 | 5 110 | This document may not, in whole or part, be copied, photocopied, reproduced or translated | without prior consent from the CEO, Unitywater. | Table 5. Contaminant release limits to waters at the Noosa STP | Quality | Median | Maximum | Characteristic | Faecal Coliforms | 150 cfu/100ml (for 5 consecutive | Four (4) out of five (5) samples | samples collected at not less than six | containing less than 600 | cfu/100mL | (6) day intervals) | 4.0 | Burgess Creek Monitoring Program | The Burgess Creek REMP consists of seven monitoring sites: Six on the western branch/main | branch and one on the eastern branch of Burgess Creek. A description of the Burgess Creek | monitoring sites is in Table 6, and a map of their corresponding locations is in Figure 4. The | parameters measured as part of this monitoring program and the limits of detection are in | Table 7. All water sampling is conducted in accordance with the Water Quality Sampling | Manual, produced by the Department of Environment and Science. | This document may not, in whole or part, be copied, photocopied, reproduced or translated | without prior consent from the CEO, Unitywater. | Table 6. Description of Burgess Creek monitoring sites | Sampling | Monitoring Site Description | Distance to River | Site | Mouth (km) | Main Branch Castaways Beach at the creek mouth 120m | downstream from the 'B1' sampling point. | SW3 | 0 | GPS: S26°25.492’ E153°06.529’ | Main Branch David Low Way, Sunrise Beach. Downstream | of the stormwater pipe under the bridge. 120m upstream of | B1 | 0.2 | the creek mouth. | GPS: S26°25.502’ E153°06.414’ | Main Branch 150m west of the end of Dame Patti Drive, | B5 | Sunrise Beach | 2.0 | GPS: S26°25.044’ E153°05.788’ | Western Branch Wallum Lane - Rotary Way, Noosa STP, | Noosa Heads. 250m downstream of the treated wastewater | B6 | 2.5 | discharge pipe and B3 site location. | GPS: S26°24.899’ E153°05.587’ | Western branch Wallum Lane – Rotary Way, Noosa Sewage | Treatment Plant. Downstream of the treated wastewater | B3 | 2.8 | discharge pipe. | GPS: S26°24.76602', E153°05.46402' | Eastern Branch Ben Lexcen Drive, Sunrise Beach. 150m | B2 | 2.9 | northwest of Girraween Sports Complex. | GPS: S26°24.654’ E153°05.736’ | Western branch ephemeral stream located 230m west of the | Eenie Creek/Langura Street roundabout and accessed via | B8 | 3.0 | Eenie Ck Rd, Noosa Heads. | GPS: S26°24.690’ E153°05.430’ | Western Branch historic upstream sampling point. 700m | B4* | 3.5 | upstream of the treated wastewater discharge pipe. | Note: Asterix (*) denotes site that is no longer monitored. | This document may not, in whole or part, be copied, photocopied, reproduced or translated | without prior consent from the CEO, Unitywater. | Burgess Creek | Receiving Environment Monitoring Program | Figure 4. The location of monitoring sites within the Burgess Creek REMP. | This document may not, in whole or part, be copied, photocopied, reproduced or translated | without prior consent from the CEO, Unitywater. | Table 7. List of water quality characteristics measured as part of the | Burgess Creek REMP. | Parameters | Units | Limits of Detection | E.coli | cfu/100mL | 1 | Faecal Coliforms | cfu/100mL | 1 | Enterococci | cfu/100mL | 1 | pH | pHU | 0.1 | Temperature | °C | 0.01 | Dissolved Oxygen | mg/L | 0.1 | μS/cm | Conductivity | 5 | Ammonia | mg/L | 0.005 | NOx | mg/L | 0.005 | Phosphate | mg/L | 0.005 | Total Nitrogen | mg/L | 0.01 | Total Phosphorus | mg/L | 0.01 | μg/L | Chlorophyll a | 1 | Chlorophyll a: Pheophytin ratio | ratio | Not applicable | Suspended Solids | mg/L | 2 | Flow Rate | Not Applicable | Not applicable | Note: The estimated flow rate has been converted into a rating from zero to five based on the | estimated flow rate at each monitoring site, as calculated previously (Lowe, 2016). | 5.0 Results | In 2021, sampling was conducted monthly as scheduled for 2021, with 12 sampling events | undertaken on the following dates: | • | • | 20 January 2021; | 8 July 2021; | • | • | 4 February 2021; | 5 August 2021; | • | • | 10 March 2021; | 29 September 2021; | • | • | 21 April 2021; | 14 October 2021; | • | • | 19 May 2021; | 11 November 2021 | • | • | 9 June 2021; | 10 December 2021. | All samples were collected and analysed from monitoring sites B1, B2, B3, B6 and SW3 | throughout the Calendar year. At monitoring site B5, samples were collected and analysed | from 11 out of 12 sampling events. Sampling was not undertaken in July due to restricted | access to the site. At monitoring site B8, samples were collected and analysed from 3 of 12 | sampling events. B8 is located within an ephemeral section of the Creek and only contains | surface water when it rains or immediately following rain. This prevented the collection of water | quality samples and was the reason for the absence of water quality parameter | concentrations. | 5.1 | Climatic Conditions | Long-term rainfall and temperature data were collected from the SILO Climate Data 1 within | the monitoring area for the Burgess Creek Water Quality Monitoring Program at the | following coordinate location: | • | Latitude: -26.40 degrees south. | • | Longitude: 153.10 degrees east. | SILO represents a gridded dataset based on records provided by the Bureau of | Meteorology (BoM). The data is then processed to fill gaps in data and produce a spatially | complete dataset (Queensland Government, 2021). A summary of monthly averages of the | SILO long-term data is in Figure 5 and Figure 6. The following general trends were | observed in the SILO data: | • Higher monthly rainfall averages during January, March, April, November, and | December, the "Wet Season". | • Lower mean monthly rainfall between May through to October, the "Dry Season". | • In 2021, the total rainfall record from SILO was 1613.40mm, compared to | 2014.90mm of rainfall in 2020. | • Rainfall received in 2021 was below the long-term average annual rainfall of | 1771.82mm recorded since 2010. | Figure 5. 2021 Monthly Climatic Data | 300 | 25 | Total Monthly Value (mm) | 250 | 20 | Temperature (C) | 200 | 15 | 150 | 10 | 100 | 5 | 50 | 0 | 0 | January | April | November | December | February | March | May | June | July | August | September | October | Month (2021) | Total Evaporation (mm) | Total Rainfall (mm) | Mean Rainfall (mm) for years 1996-2022 | Average Maximum Temperature (°C) | Average Minimum Temperature (°C) | Figure 6. 2021 Daily Rainfall. | 100 | 80 | Rainfall (mm) | 60 | 40 | 20 | January | March | April | May | July | November | February | June | August | September | October | December | Month (2021) | 5.2 Summary Statistics | Summary statistics of nutrient concentrations and microbiological indicators across all | monitoring sites are in Appendix A - Summary statistics of nutrient concentrations and | microbiological indicators at each monitoring site | 5.3 Spatial Trends | Figure 7 to Figure 22 shows the spatial variability of average concentrations with error | bars of water quality parameters measured within Burgess Creek against distance from the | mouth. These figures demonstrate how the Noosa STP and catchment sources affect water | quality spatially (longitudinally) within Burgess Creek. | The following trends were noted in the monitoring data: | • | E.coli, enterococci and thermotolerant (faecal) coliform concentrations at B3 | immediately downstream of the treated wastewater discharge pipe remain below | upstream values represented in B8 and B2. Throughout the catchment E.coli remains | below average background concentrations at B8. Whereas the average | concentrations of enterococci and thermotolerant (faecal) coliform at B1 and SW3 | are highest at the mouth and decreases with increasing distance from the mouth of | the Burgess Creek Catchment (Figure 7, Figure 8, Figure 9) | • | Ammonia concentration was highest at B3 and decreased consistently to SW3. | Ammonia returned to concentrations similar to background site B2 and B8 close to | the mouth (Figure 10). | • | Nitrate & Nitrite (NOx), Total Nitrogen, Filter Reactive Phosphorous and Total | Phosphorous follow a similar trend with the highest concentrations recorded at B3 | immediately downstream of the STP outfall, declining slightly (though remaining | relatively high comparative to background) downstream to the point of discharge into | the ocean. Concentrations of these nutrients were relatively low at B8 and B2 | upstream of the STP outfall (Figure 11, Figure 12, Figure 13, Figure 14). | • | Temperature, dissolved oxygen, pH and conductivity were low upstream of the STP | outfall point, notably increasing at the outfall point (or just downstream), before | decreasing slightly (or remaining similar) with distance downstream of the STP outfall | (Figure 15, Figure 16, Figure 17, Figure 18). | • | Chlorophyll a was highest upstream of the STP outfall, represented in B8. Recorded | values notably decreased at B3, immediately downstream of the outfall point, before | remaining consistent at monitoring sites further downstream towards the ocean | (Figure 19) | • | Chlorophyll a to pheophytin ratio and suspended solids results showed an increase | down the catchment with the highest concentration at B1 before decreasing to | background levels at SW3 (Figure 20, Figure 21). | • | Estimated water flow was the highest at the point of the STP outfall and remained | relatively consistent at sites downstream (Figure 22). | Figure 7. The spatial variability of the average concentration of E.coli during 2021. | 900 | 800 | 700 | 600 | E.coli (cfu/100mL) | 500 | B8 | SW3 | 400 | B1 | 300 | B5 | 200 | B2 | B6 | 100 | B3 - STP Outfall | 0 | -0.2 | 0 | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 | 3 | 3.2 | Distance from the Mouth (km) | Figure 8. The spatial variability of the average concentration of Intestinal Enterococci during | 2021. | 1200 | 1000 | Intestinal Enterococci (cfu/100mL) | 800 | B1 | SW3 | 600 | B5 | 400 | B8 | B6 | 200 | B2 | B3 - STP Outfall | 0 | -0.2 | 0 | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 | 3 | 3.2 | Distance from the Mouth (km) | Figure 9. The spatial variability of the average concentration of Thermotolerant (faecal) | Coliforms during 2021. | 1600 | 1400 | Thermotolerant Coliforms (cfu/100mL) | 1200 | 1000 | SW3 B1 | B8 | 800 | B5 | 600 | 400 | B6 | B2 | B3 - STP Outfall | -0.2 | 0.2 | 0.4 | 0.6 | 0.8 | 1.2 | 1.4 | 1.6 | 1.8 | 2.2 | 2.4 | 2.6 | 2.8 | 3.2 | Distance from the Mouth (km) | Figure 10. The spatial variability of the average concentration of Ammonia during 2021. | 0.18 | 0.16 | 0.14 | 0.12 | Ammonia (mg/L) | B3 - STP | 0.10 | Outfall | B6 | 0.08 | 0.06 | B8 | B5 | 0.04 | SW3 | B1 | B2 | 0.02 | 0.00 | -0.2 | 0 | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 | 3 | 3.2 | Distance from the Mouth (km) | Figure 11. The spatial variability of the average concentration of Nitrate & Nitrite (NOx) during | 2021. | 3.50 | 3.00 | B6 | 2.50 | B3 - STP Outfall | Nitrate & Nitrite (mg/L) | SW3 | 2.00 | B5 | B1 | 1.50 | 1.00 | 0.50 | B2 B8 | 0.00 | -0.2 | 0 | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 | 3 | 3.2 | Distance from the Mouth (km) | Figure 12. The spatial variability of the average concentration of Total Nitrogen during 2021. | 5.00 | B3 - STP Outfall | 4.50 | B6 | 4.00 | 3.50 | Total Nitrogen (mg/L) | B1 | 3.00 | B5 | 2.50 | SW3 | 2.00 | 1.50 | B8 | 1.00 | B2 | 0.50 | 0.00 | -0.2 | 0.2 | 0.4 | 0.6 | 0.8 | 1.2 | 1.4 | 1.6 | 1.8 | 2.2 | 2.4 | 2.6 | 2.8 | 3.2 | Distance from the Mouth (km) | Figure 13. The spatial variability of the average concentration of Filter Reactive Phosphorus | during 2021. | 0.16 | 0.14 | Filter Reactive Phosphorus (mg/L) | B3 - STP | B6 | 0.12 | Outfall | B5 | SW3 | 0.10 | B1 | 0.08 | 0.06 | 0.04 | 0.02 | B2 | B8 | 0.00 | -0.2 | 0 | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 | 3 | 3.2 | Distance from the Mouth (km) | Figure 14. The spatial variability of the average concentration of Total Phosphorus during 2021. | 0.25 | 0.20 | B3 - | B6 | STP | Total Phosphorus (mg/L) | Outfall | B5 | 0.15 | SW3 | B1 | 0.10 | 0.05 | B2B8 | 0.00 | -0.2 | 0.2 | 0.4 | 0.6 | 0.8 | 1.2 | 1.4 | 1.6 | 1.8 | 2.2 | 2.4 | 2.6 | 2.8 | 3.2 | Distance from the Mouth (km) | Figure 15. The spatial variability of average temperature during 2021 | 29 | 27 | B3 - STP | B6 | Outfall | 25 | Temperature (0C) | B5 | SW3 | 23 | B1 | 21 | B8 | B2 | 19 | 17 | 15 | -0.2 | 0 | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 | 3 | 3.2 | Distance from the Mouth (km) | Figure 16. The spatial variability of the average concentration of dissolved oxygen during 2021 | 9 | 8 | B3 - STP | Outfall | 7 | B6 | Dissovled Oxygen (mg/L) | 6 | B5 | 5 | SW3 | B2 | 4 | B1 | 3 | B8 | 2 | 1 | -0.2 | 0.2 | 0.4 | 0.6 | 0.8 | 1.2 | 1.4 | 1.6 | 1.8 | 2.2 | 2.4 | 2.6 | 2.8 | 3.2 | Distance from the Mouth (km) | Figure 17. The spatial variability of average pH during 2021 | 8 | B6 | B3 - STP | SW3 | B5 | Outfall | B1 | 7 | pH | 6 | B2 | 5 | B8 | 4 | 3 | -0.2 | 0 | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 | 3 | 3.2 | Distance from the Mouth (km) | Figure 18. The spatial variability of average Conductivity during 2021. | 2000 | B3 - | 1800 | STP | B6 | Outfall | 1600 | 1400 | B5 | Condcutivity (μS/cm3) | 1200 | SW3 | B1 | 1000 | 800 | 600 | 400 | 200 | B2B8 | -0.2 | 0.2 | 0.4 | 0.6 | 0.8 | 1.2 | 1.4 | 1.6 | 1.8 | 2.2 | 2.4 | 2.6 | 2.8 | 3.2 | Distance from the Mouth (km) | Figure 19. The spatial variability of the average concentration of Chlorophyll a during 2021. | 3 | 2 | Chlorophyll a (μg/L) | B8 | 2 | B3 - STP Outfall | SW3 B1 | B6 | B5 | 1 | B2 | 1 | 0 | -0.2 | 0 | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 | 3 | 3.2 | Distance from the Mouth (km) | Figure 20. The spatial variability of the average Chlorophyll a: Pheophytin Ratio during 2021. | 1.31 | 1.26 | Chlorophyll a: Pheophytin Ratio | 1.21 | 1.16 | B1 | 1.11 | B3 - STP | Outfall | B5 | 1.06 | B6 | B2 | SW3 | 1.01 | B8 | 0.96 | -0.2 | 0.2 | 0.4 | 0.6 | 0.8 | 1.2 | 1.4 | 1.6 | 1.8 | 2.2 | 2.4 | 2.6 | 2.8 | 3.2 | Distance from the Mouth (km) | Figure 21. The spatial variability of the average concentration of Total Suspended Solids during | 2021. | 10 | 9 | 8 | Total Suspended Solids (mg/L) | 7 | B1 | B3 - STP | 6 | B5 | Outfall | B6 | 5 | 4 | SW3 | B8 | 3 | B2 | 2 | 1 | 0 | -0.2 | 0 | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 | 3 | 3.2 | Distance from the Mouth (km) | Figure 22. The spatial variability of the average estimated water flow during 2021. | 4 | B3 - STP | 3 | Outfall | B1 | B6 | B5 | Estimated Water Flow | SW3 | B2 | B8 | 2 | 1 | -0.2 | 0.2 | 0.4 | 0.6 | 0.8 | 1.2 | 1.4 | 1.6 | 1.8 | 2.2 | 2.4 | 2.6 | 2.8 | 3.2 | Distance from the Mouth (km) | 5.4 Temporal Variability | . | Figure 23 to Figure 38 shows the variability of water quality parameters measured at each | monitoring site in the 2021 calendar year. Where no samples were collected, no value is | shown. It should be noted that: | • | Monitoring site B8 has no data for March, April, June, July, August, September, | October, November, and December 2021. | • | Monitoring Site B5 has no data for July 2021. | The following trends were noted in the concentration of the following water quality | parameters: | • | Higher microbiological indicator (E.coli, enterococci and faecal coliforms) levels at | several sites (particularly B1, B2, B5, B6, B8 and SW3) following periods of high | intensity rainfall events. | • | Ammonia at B8 remained low throughout the year with the exception of a spike in | December for all monitoring sites apart from B2. | • | Nitrate & Nitrite (NOx), was highly variable throughout the year (except for B2 and B8 | remaining low throughout). | • | A peak in total nitrogen occurred at B1 in March prior to a decrease in concentration | below B3, B6 and B5 for the remainder of the year. The other sites were consistent | throughout the year. | • | Filter reactive phosphorus and total phosphorus had a spike in concentration at most | sites in February (except for B2 and B8). | • | Dissolved Oxygen remained relatively consistent with only slight variability at all | monitoring sites, except for B5 which spiked in June. | • | pH remained constant throughout the year with all sites remaining between 6.5 and 8 | pH units, except for B2 and B8 which remained below 6 pH units. | • | Conductivity for most monitoring sites (except for B2 and B8) fell in May and spiked in | November. | • | Chlorophyll a varied throughout the year with a notable spike at B8 in May. | • | Chloropyll a pheophytin ratio spiked at all sites in August and December. | • | High variability in suspended solids with notable spikes across all sites in February, | May and November with an additional outlying spike occurring at B1 in September. | • | Water flow remained between 2 and 4 throughout the year across most sites with the | exception on B8 that only experienced water flow in May and B2 having a reduction in | flow in September. | Figure 23. The temporal variability of the concentration of E.coli during 2021. | 4500 | 4000 | 3500 | E.coli (cfu/100mL) | 3000 | 2500 | 2000 | 1500 | 1000 | 500 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 24. The temporal variability of the concentration of intestinal enterococci during 2021. | 5000 | 4500 | Intestinal Enterococci (cfu/100mL) | 4000 | 3500 | 3000 | 2500 | 2000 | 1500 | 1000 | 500 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 25. The temporal variability of the concentration of thermotolerant (faecal) coliforms | during 2021. | 6000 | Thermotolerant Coliforms (cfu/100mL) | 5000 | 4000 | 3000 | 2000 | 1000 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 26. The temporal variability of the concentration of ammonia during 2021. | 0.9 | 0.8 | 0.7 | 0.6 | Ammonia (mg/L) | 0.5 | 0.4 | 0.3 | 0.2 | 0.1 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 27. The temporal variability of the concentration of nitrate and nitrite (NOx) during 2021. | 4.5 | 4 | 3.5 | 3 | Nitrate + Nitrite (mg/L) | 2.5 | 2 | 1.5 | 1 | 0.5 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 28. The temporal variability of the concentration of total nitrogen during 2021. | 8 | 7 | 6 | Total Nitrogen (mg/L) | 5 | 4 | 3 | 2 | 1 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 29. The temporal variability of the concentration of filter reactive phosphorus during | 2021. | 0.45 | 0.4 | 0.35 | 0.3 | Phosphate (mg/L) | 0.25 | 0.2 | 0.15 | 0.1 | 0.05 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 30. The temporal variability of the concentration of total phosphorus during 2021. | 0.5 | 0.45 | 0.4 | 0.35 | Total Phosphorus (mg/L) | 0.3 | 0.25 | 0.2 | 0.15 | 0.1 | 0.05 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 31. The temporal variability of temperature during 2021. | 30 | 28 | 26 | Temperatture (°C) | 24 | 22 | 20 | 18 | 16 | 14 | 12 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 32. The temporal variability of the concentration of dissolved oxygen during 2021. | 10 | 9 | 8 | Dissolved Oxygen (mg/L) | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 33. The temporal variability of pH during 2021. | 8 | 7.5 | 7 | pH | 6.5 | 6 | 5.5 | 5 | 4.5 | 4 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 34.The temporal variability of electrical conductivity during 2021. | 2500 | 2000 | Electrical Conductivity (μS/cm3) | 1500 | 1000 | 500 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 35. The temporal variability of the concentration of chlorophyll a during 2021. | 3.5 | 3 | 2.5 | Chlorophyll a (μg/L) | 2 | 1.5 | 1 | 0.5 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 36. The temporal variability of the concentration of chlorophyll a: Pheophytin ratio during | 2021. | 2.6 | 2.4 | 2.2 | Chlorophyll a:phenophytin ratio | 2 | 1.8 | 1.6 | 1.4 | 1.2 | 1 | 0.8 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 37. The temporal variability of the concentration of total suspended solids during 2021. | 35 | 30 | 25 | Total Suspended Solids (mg/L) | 20 | 15 | 10 | 5 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | Figure 38. The temporal variability of the concentration of estimated water flow during 2021. | 4 | 3 | Estimated Water Flow | 2 | 1 | 0 | Month Sampled | Site SW3 | Site B1 | Site B5 | Site B6 | Site B3 | Site B8 | Site B2 | 5.5 Long term variability | Figure 39 to Figure 52 shows the long-term variability of microbiological and nutrient | indicators measured at each monitoring site from 2015 to 2021. Where no samples were | collected, no value is shown. As per recommendations in the 2017 and 2020 Annual | Monitoring Report, longer-term assessment using historical monitoring data has been | included to depict any apparent temporal or spatial trends in the data sets and potential | influences of the treated wastewater release. These figures present the long-term | measurements collected for microbiological indicators (E.coli, Enterococci and | Thermotolerant Coliform) and key nutrient indicators (Total Phosphorus, Total Nitrogen and | Chlorophyll a) across all monitoring sites. | The following trends were noted in the monitoring data: | • | E.coli has no clear long-term trend within the data collected from any of the | monitoring sites with the exception of B8 which shows increasing concentration with | time. | • | Thermotolerant coliforms have a decreasing long-term trend at monitoring site | SW3. Monitoring site B3, B8, B5 and B6 have an increasing trend and monitoring | site B1 and B2 showed no clear long-term trend within the data collected from 2015 | to 2021. | • | Enterococci had an increasing long-term trend at monitoring sites B8. Monitoring | site B2, B5, B6 and SW3 have a decreasing trend and monitoring site B3 and B1 | and showed no clear long-term trend within the data collected from 2015 to 2021. | • | Total phosphorus and ammonia have no clear long-term trend within the data | collected from any of the monitoring sites. | • | Total Nitrogen has a decreasing long-term trend at monitoring site SW3. Monitoring | site B1, B3, B5, B6 and B8 have an increasing trend and monitoring site B2 showed | no clear long-term trend within the long term data collected. | Figure 39. Long term variability of microbiological indicators at B1 | 7200 | 6600 | 6000 | 5400 | Colony forming units | 4800 | 4200 | 3600 | 3000 | 2400 | 1800 | 1200 | 600 | 0 | 01/2015 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 11/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 09/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 07/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | E. coli | Thermotolerant coliforms | Intestinal enterococci | Figure 40. Long term variability of key nutrient indicators at B1 | 9 | 8 | 7 | 6 | 5 | mg/L | 4 | 3 | 2 | 1 | 0 | 01/2015 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 11/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 09/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 07/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | Ammonia as N | Total Nitrogen as N | Total Phosphorus as P | Figure 41. Long term variability of microbiological indicators at B2 | 4500 | 4000 | Colony forming units | 3500 | 3000 | 2500 | 2000 | 1500 | 1000 | 500 | 0 | 01/2015 | 11/2016 | 09/2018 | 07/2020 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | E. coli | Thermotolerant coliforms | Intestinal enterococci | Figure 42. Long term variability of key nutrient indicators at B2 | 3.5 | 3 | 2.5 | 2 | mg/L | 1.5 | 1 | 0.5 | 0 | 01/2015 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 11/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 09/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 07/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | Ammonia as N | Total Nitrogen as N | Total Phosphorus as P | Figure 43.Long term variability of microbiological indicators at B3 | 800 | 700 | Colony forming units | 600 | 500 | 400 | 300 | 200 | 100 | 0 | 01/2015 | 11/2016 | 09/2018 | 07/2020 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | E. coli | Thermotolerant coliforms | Intestinal enterococci | Figure 44. Long term variability of key nutrient indicators at B3 | 10 | 9 | 8 | 7 | 6 | mg/L | 5 | 4 | 3 | 2 | 1 | 0 | 01/2015 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 11/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 09/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 07/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | Ammonia as N | Total Nitrogen as N | Total Phosphorus as P | Figure 45. Long term variability of microbiological indicators at B5 | 6000 | Colony forming units | 5000 | 4000 | 3000 | 2000 | 1000 | 0 | 01/2015 | 11/2016 | 09/2018 | 07/2020 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | E. coli | Thermotolerant coliforms | Intestinal enterococci | Figure 46. Long term variability of key nutrient indicators at B5 | 8 | 7 | 6 | 5 | mg/L | 4 | 3 | 2 | 1 | 0 | 01/2015 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 11/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 09/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 07/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | Ammonia as N | Total Nitrogen as N | Total Phosphorus as P | Figure 47. Long term variability of microbiological indicators at B6 | 5500 | 5000 | 4500 | Colony forming units | 4000 | 3500 | 3000 | 2500 | 2000 | 1500 | 1000 | 500 | 0 | 01/2015 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 11/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 09/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 07/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | E. coli | Thermotolerant coliforms | Intestinal enterococci | Figure 48.Long term variability of key nutrient indicators at B6 | 9 | 8 | 7 | 6 | 5 | mg/L | 4 | 3 | 2 | 1 | 0 | 01/2015 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 11/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 09/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 07/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | Ammonia as N | Total Nitrogen as N | Total Phosphorus as P | Figure 49. Long term variability of microbiological indicators at B8 | 1600 | 1400 | Colony forming units | 1200 | 1000 | 800 | 600 | 400 | 200 | 0 | 10/2015 | 05/2017 | 01/2019 | 09/2020 | 12/2015 | 02/2016 | 05/2016 | 07/2016 | 10/2016 | 12/2016 | 03/2017 | 08/2017 | 10/2017 | 01/2018 | 03/2018 | 06/2018 | 08/2018 | 10/2018 | 03/2019 | 06/2019 | 08/2019 | 11/2019 | 01/2020 | 04/2020 | 06/2020 | 11/2020 | 02/2021 | 04/2021 | Date | E. coli | Thermotolerant coliforms | Intestinal enterococci | Figure 50. Long term variability of key nutrient indicators at B8 | 4.5 | 4 | 3.5 | 3 | 2.5 | mg/L | 2 | 1.5 | 1 | 0.5 | 0 | 10/2015 | 12/2015 | 02/2016 | 05/2016 | 07/2016 | 10/2016 | 12/2016 | 03/2017 | 05/2017 | 08/2017 | 10/2017 | 01/2018 | 03/2018 | 06/2018 | 08/2018 | 10/2018 | 01/2019 | 03/2019 | 06/2019 | 08/2019 | 11/2019 | 01/2020 | 04/2020 | 06/2020 | 09/2020 | 11/2020 | 02/2021 | 04/2021 | Date | Ammonia as N | Total Nitrogen as N | Total Phosphorus as P | Figure 51. Long term variability of microbiological indicators at SW3 | 10500 | 9000 | Colony forming units | 7500 | 6000 | 4500 | 3000 | 1500 | 0 | 01/2015 | 03/2015 | 05/2015 | 08/2015 | 10/2015 | 01/2016 | 03/2016 | 06/2016 | 08/2016 | 11/2016 | 01/2017 | 04/2017 | 06/2017 | 09/2017 | 11/2017 | 01/2018 | 04/2018 | 06/2018 | 09/2018 | 11/2018 | 02/2019 | 04/2019 | 07/2019 | 09/2019 | 12/2019 | 02/2020 | 05/2020 | 07/2020 | 10/2020 | 12/2020 | 02/2021 | 05/2021 | 07/2021 | 10/2021 | 12/2021 | Date | E. coli | Thermotolerant coliforms | Intestinal enterococci | Figure 52. Long term variability of key nutrient indicators at SW3 | 4.5 | 4 | 3.5 | 3 | 2.5 | mg/L | 2 | 1.5 | 1 | 0.5 | 0 | 07/2017 | 09/2017 | 11/2017 | 02/2018 | 04/2018 | 07/2018 | 09/2018 | 12/2018 | 02/2019 | 05/2019 | 07/2019 | 10/2019 | 12/2019 | 03/2020 | 05/2020 | 07/2020 | 10/2020 | 12/2020 | 03/2021 | 05/2021 | 08/2021 | 10/2021 | Date | Ammonia as N | Total Nitrogen as N | Total Phosphorus as P | 5.6 Statistical Comparison of 2020 and 2021 Monitoring Data | Students' t-tests with unequal variances assumed were used to test whether 2021 | monitoring data collected at each site were statistically similar or different from the | monitoring data collected in 2020. | Mean water quality data used for statistical analysis amongst 2021 and 2020 calendar | years are in Table 8. This data summarises the results provided within Appendix A - | Summary statistics of nutrient concentrations and microbiological indicators at each | monitoring site and allows easier comparison of the mean values between years. | The p-values generated by the statistical analysis conducted between the 2021 and 2020 | data are in Table 8 and Table 9. | Most of the water quality parameters across all monitoring sites demonstrated no | statistically significant difference between 2020 and 2021. Of the 105 statistical tests | conducted, three statistically significant differences (p ≤ 0.05) were found. Of those, two | were a reported increase in concentration from the most recent year's monitoring program. | A summary of the statistically significant differences includes: | • | Monitoring Site B2 | o Decrease in the concentration of Total Nitrogen as N; | o Increase in pH. | • | Monitoring Site B5 | o Increase in Dissolved Oxygen. | Burgess Creek | Receiving Environment Monitoring Program | Table 8. The mean water quality data used for statistical analysis amongst 2021 and 2020 calendar years. | Nitrate | Total | Total | Chloro-a | Monitoring | Thermotolerant | Intestinal | Ammonia | Phosphate | Dissolved | Chlorophyll | Suspended | Water | Year | E.coli | pH | Conductivity | + Nitrite | Nitrogen | Phosphorus | Phenophytin | Site | coliforms | enterococci | as N | as P | Oxygen | a | Solids | Flow | as N | as N | as P | ratio | mg/L | mg/L | mg/L | mg/L | mg/L | mg/L | pHU | uS/cm | ug/L | ratio | mg/L | cfu/100mL | cfu/100mL | cfu/100mL | B1 | 2021 | 12 | 376.92 | 916.08 | 646.67 | 0.024 | 1.65 | 0.08 | 3.07 | 0.114 | 3.82 | 7.01 | 1057.08 | 1.08 | 1.03 | 6.83 | 2.83 | 2020 | 12 | 100.42 | 576.08 | 370.50 | 0.025 | 1.67 | 0.07 | 2.90 | 0.097 | 4.19 | 7.14 | 1122.58 | 1.08 | 0.98 | 3.67 | 2.92 | B2 | 2021 | 12 | 170.00 | 289.67 | 97.33 | 0.022 | 0.009 | 0.005 | 0.706 | 0.013 | 4.34 | 5.31 | 179.00 | 1.18 | 1.00 | 2.92 | 2.58 | 2020 | 12 | 89.92 | 249.50 | 120.42 | 0.025 | 0.008 | 0.007 | 0.878 | 0.022 | 3.88 | 5.10 | 168.58 | 2.61 | 1.03 | 7.92 | 2.75 | B3 | 2021 | 12 | 12.00 | 43.83 | 7.50 | 0.096 | 2.89 | 0.12 | 4.25 | 0.185 | 7.49 | 7.32 | 1757.50 | 1.15 | 0.99 | 4.00 | 3.08 | 2020 | 10 | 26.25 | 54.33 | 97.33 | 0.020 | 2.37 | 3.96 | 0.08 | 0.154 | 6.93 | 7.56 | 1811.33 | 1.16 | 1.00 | 5.42 | 3.08 | B5 | 2021 | 11 | 214.27 | 735.45 | 458.45 | 0.041 | 1.79 | 0.11 | 2.92 | 0.162 | 5.25 | 7.33 | 1378.09 | 1.06 | 1.00 | 5.73 | 2.82 | 2020 | 12 | 150.25 | 201.17 | 657.33 | 0.017 | 1.40 | 2.77 | 0.09 | 0.128 | 4.63 | 7.30 | 1302.42 | 1.10 | 0.99 | 7.42 | 2.75 | B6 | 2021 | 11 | 156.92 | 363.50 | 211.00 | 0.082 | 2.84 | 0.12 | 4.18 | 0.192 | 7.01 | 7.55 | 1730.83 | 1.14 | 1.00 | 5.33 | 2.83 | 2020 | 12 | 73.73 | 133.36 | 280.18 | 0.020 | 2.24 | 3.67 | 0.08 | 0.153 | 6.32 | 7.63 | 1855.45 | 1.12 | 1.00 | 7.55 | 2.91 | B8 | 2021 | 3 | 487.67 | 815.00 | 379.67 | 0.04 | 0.03 | 0.01 | 1.287 | 0.017 | 2.70 | 4.40 | 115.33 | 1.73 | 1.00 | 3.67 | 2.00 | 2020 | 10 | 54.33 | 115.61 | 213.89 | 0.05 | 0.02 | 1.73 | 0.010 | 0.034 | 2.01 | 4.40 | 159.22 | 13.33 | 1.08 | 6.78 | 1.20 | SW3 | 2021 | 12 | 437.67 | 943.33 | 642.42 | 0.026 | 1.71 | 0.08 | 2.77 | 0.118 | 3.88 | 7.18 | 1165.58 | 1.23 | 1.00 | 3.83 | 2.50 | 2020 | 12 | 131.27 | 298.73 | 589.73 | 0.027 | 1.53 | 2.81 | 0.06 | 0.094 | 4.89 | 7.19 | 1266.25 | 1.47 | 1.03 | 4.33 | 2.67 | Table 9. Results of the Students' t-test comparing 2021 and 2020 water quality data. | Nitrate + | Total | Total | Chloro-a | Monitoring | Intestinal | Thermotolerant | Ammonia as | Phosphate | Dissolved | Chlorophyll | Suspended | Water | E.coli | Nitrite as | Nitrogen as | Phosphorus | pH | Conductivity | Phenophytin | Site | enterococci | coliforms | N | as P | Oxygen | a | Solids | Flow | N | N | as P | ratio | 0.409 | 0.436 | 0.464 | 0.927 | 0.921 | 0.662 | 0.751 | 0.233 | 0.343 | 0.120 | 0.632 | 0.842 | 0.170 | 0.332 | 0.754 | B1 | B2 | 0.194 | 0.524 | 0.829 | 0.217 | 0.421 | 0.015* | 0.083 | 0.168 | 0.488 | 0.026* | 0.382 | 0.243 | 0.170 | 0.107 | 0.504 | 0.5402 | 0.4604 | 0.3497 | 0.2926 | 0.1984 | 0.1834 | 0.5003 | 0.3517 | 0.1631 | 0.1565 | 0.7858 | 0.9598 | 0.3506 | 0.4740 | 1.000 | B3 | 0.418 | 0.770 | 0.183 | 0.415 | 0.063 | 0.228 | 0.542 | 0.234 | 0.315 | 0.759 | 0.642 | 0.634 | 0.351 | 0.604 | 1.000 | B5 | 0.5555 | 0.7974 | 0.6582 | 0.2111 | 0.1570 | 0.2024 | 0.3139 | 0.3134 | 0.0455* | 0.3562 | 0.4632 | 0.8777 | #DIV/0! | 0.4681 | 0.6761 | B6 | 0.343 | 0.334 | 0.420 | 0.549 | 0.667 | 0.516 | 0.670 | 0.598 | 0.423 | 0.506 | 0.547 | 0.362 | 0.423 | 0.423 | 1.000 | B8 | SW3 | 0.4144 | 0.4839 | 0.3292 | 0.8567 | 0.6973 | 0.2752 | 0.8908 | 0.0715 | 0.1537 | 0.8619 | 0.5299 | 0.3639 | 0.1705 | 0.7806 | 0.1661 | Note: Asterix (*) denotes significant difference between 2021 and 2020 | Burgess Creek | Receiving Environment Monitoring Program | 5.7 Compliance of 2021 data with Water Quality Objectives | The 2021 water quality data measured for each parameter, during each sampling event | (month) and at each monitoring site was compared with the applicable water quality | objectives for a moderately disturbed Lowland Freshwater Creek. These limits are in Table | 2. The percentage compliance of water quality parameters measured in 2021 with Burgess | Creek Water Quality Objectives are in Table 10. | Table 10. Percentage (%) compliance of water quality parameters measured in 2021 within | Burgess Creek water quality objectives. | Water Quality | B1 | B2 | B3 | B5 | B6 | B8 | SW3 | Parameter | pH | 100 | 100 | 100 | 100 | 100 | 100 | 100 | Conductivity | 0 | 100 | 0 | 0 | 0 | 100 | 0 | Ammonia | 58 | 42 | 42 | 91 | 58 | 0 | 17 | NOx | 0 | 100 | 0 | 0 | 0 | 100 | 0 | Phosphate | 0 | 100 | 0 | 0 | 0 | 100 | 0 | Total Nitrogen | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Total | 0 | 100 | 0 | 0 | 0 | 100 | 0 | Phosphorus | Chlorophyll a | 100 | 100 | 100 | 100 | 100 | 100 | 100 | Suspended | 75 | 92 | 83 | 73 | 75 | 100 | 92 | Solids | Overall | 37 | 81 | 36 | 40 | 37 | 78 | 34 | Overall, the water quality within Burgess Creek was 49% compliant with the prescribed | water quality objectives. This represents a slight increasing trend in overall water quality | compared to previous assessments. Consistent with previous years, no monitoring site was | 100% compliant with the water quality objectives for Burgess Creek. The historical | percentage compliance at each monitoring site and overall compliance of Burgess Creek | with prescribed water objectives is provided in Figure 53. | Monitoring site SW3 was the site with the lowest percentage compliance of 34% with the | water quality objectives for Burgess Creek, similarly to 2018, 2019 and 2020 results. | Monitoring site B2 had the highest percentage compliance with the water quality objectives | for Burgess Creek (81% compliance). It should be noted low compliance of Conductivity | represents site proximity to the ocean, compared to typically fresh WQOs, and influences | overall compliance percentage. | Burgess Creek | Receiving Environment Monitoring Program | Figure 53. The historical percentage compliance of each monitoring site and overall | percentage compliance with Water Quality Objectives. | Overall Percentage Compliance with Water Quality Objectives | 80 | 70 | 60 | 50 | (%) | 40 | 30 | 20 | 10 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | Year Sampled | B1 | B2 | B3 | B4 | B5 | B6 | B8 | SW3 | Overall | 5.8 Comparison with Recreational Water Quality Limits | Table 11 provides the comparison of the percentage compliance of enterococci, | thermotolerant coliforms and E.coli against peer-reviewed primary and secondary | recreational water quality guideline limits set within the Australian and New Zealand | guidelines for fresh and marine water quality (ANZECC, 2000). The data indicates non- | compliance with enterococci across all monitoring sites, the exception is B3. | Thermotolerant coliforms achieved 100% compliance at B2 and B3 with the remaining sites | (B1, B5, B6, B8 and SW3) non-compliant. Most monitoring sites were 100% compliant with | E.coli with the exception of B1 and SW3. | Burgess Creek | Receiving Environment Monitoring Program | Table 11. Percentage compliance in 2021 with Recreational Water Quality Limits (ANZECC, | 2000) for Burgess Creek. | Biological Indicators | % Compliance at Monitoring Site | Water Quality | Guideline (ANZECC, | Parameter | B1 | B2 | B3 | B5 | B6 | B8 | SW3 | 2000) | 150 | Primary | 0 | 92 | 92 | 0 | 25 | 33 | 0 | cfu/100mL | Enterococci | 1000 | Secondary | 50 | 92 | 100 | 27 | 75 | 67 | 42 | cfu/100mL | 35 | Primary | 17 | 33 | 100 | 0 | 67 | 33 | 17 | Thermotolerant | cfu/100mL | Coliforms | 230 | Secondary | 75 | 100 | 100 | 82 | 92 | 67 | 92 | cfu/100mL | 1260 | E coli | Secondary | 92 | 100 | 100 | 100 | 100 | 100 | 92 | cfu/100mL | 5.9 Compliance of treated wastewater releases with Environmental | Authority EPPR008691113 | A review of the compliance monitoring data for Noosa STP (Table 12, Figure 54 and | Figure 55) shows that there were 0 reported non-compliances with the water quality | characteristic release limits. | Table 12. Mass Load limits at the Noosa STP for 2021 | Nutrient | Average | Nitrogen | Phosphorus | Nitrogen | Phosphorus | Parameter | Annual | 50th | 50th Percentile | Flow | Percentile | Units | ML/year | mg/L | Kg/year | mg/L | Kg/year | Limit | 5 110 | 5 | 25 550 | 1 | 5 110 | Mass Load | 3763 | 4.72 | 16 658 | 0.14 | 510 | Burgess Creek | Receiving Environment Monitoring Program | Figure 54. Mass Loads Released from Noosa STP | Kg per day released from Noosa STP | 25000 | 20000 | 15000 | 10000 | 5000 | 0 | 18/11/2020 | 2/01/2020 | 15/01/2020 | 29/01/2020 | 12/02/2020 | 26/02/2020 | 11/03/2020 | 25/03/2020 | 8/04/2020 | 22/04/2020 | 6/05/2020 | 20/05/2020 | 3/06/2020 | 17/06/2020 | 1/07/2020 | 15/07/2020 | 29/07/2020 | 12/08/2020 | 26/08/2020 | 9/09/2020 | 23/09/2020 | 7/10/2020 | 21/10/2020 | 4/11/2020 | 2/12/2020 | 16/12/2020 | Date | TN limit | TP limit | Total Nitrogen | Total Phosphorus | Figure 55. Concentration released from Noosa STP | 6 | Cocnentration (mg/L) released from | 5 | 4 | Noosa STP | 3 | 2 | 1 | 0 | 6/01/2021 | 20/01/2021 | 3/02/2021 | 17/02/2021 | 3/03/2021 | 17/03/2021 | 31/03/2021 | 14/04/2021 | 28/04/2021 | 12/05/2021 | 26/05/2021 | 9/06/2021 | 23/06/2021 | 7/07/2021 | 21/07/2021 | 4/08/2021 | 18/08/2021 | 30/08/2021 | 8/09/2021 | 22/09/2021 | 6/10/2021 | 20/10/2021 | 3/11/2021 | 17/11/2021 | 26/11/2021 | 8/12/2021 | Date | TN Limit | TP Limit | TN mg/L | TP mg/L | Burgess Creek | Receiving Environment Monitoring Program | 6.0 Discussion | This review presents the results of the Burgess Creek REMP for the 2021 calendar year and | provides an assessment of the influence of Noosa STP discharge on the receiving | environment. Specifically, this annual review ensures that the compliance obligations with the | requirements of condition G13 of the EA. Observations and comments remain consistent with | previous assessments and continuous improvement is being made to better identify trends | and provide recommendations for the Burgess Creek Receiving Environment Monitoring | Program. | During the 2021 review period, 0 non-compliances were recorded for treated wastewater | releases from the Noosa STP in association with the conditions imposed by the EA. This is | the third year in which this review is tracking non-compliance with water quality characteristic | release limits. Future reviews will track, identify trends and comment on compliance of the | Noosa STP releases with water quality characteristic release limits. | The State of the Climate 2022 Report from the Bureau of Meteorology (2022) presents a | coherent depiction of persistent, gradual climate change intertwined with inherent natural | fluctuations, established through observations, reconstructions, and climate modelling. This | interaction has resulted in alterations in extreme weather and climate conditions, including | extreme heat, heavy rainfall, coastal inundation, fire, and drought, which have had a significant | impact on the health and prosperity of both human communities and ecosystems. These | observations align with previous assessments of the Burgess Creek Catchment, which | identified precipitation and related water flows as the primary determinant of water quality | conditions in the area. | In 2021, the total rainfall was significantly lower than the previous year by 401mm and lower | than the average of the past 10 years by 158mm. This decrease in rainfall has been observed | throughout the south-east region of Australia since the late 1990s, where a reduction of around | 10 per cent in April to October rainfall has been noticed. Although, it has also been noted that | there has been an increase in the intensity of heavy rainfall events in Australia, which occur | in less than a day. These events have increased by 10 per cent or more in some regions, | particularly in the northern part of the country (Bureau of Meteorology, 2022). | Furthermore, around 60 per cent of hydrologic reference stations across Australia have | reported a decreasing trend in streamflow (Bureau of Meteorology, 2022). This was also the | case at monitoring site B8, where only 3 out of 12 sampling events could be conducted, | marking the least number of samples collected since its establishment in 2015. This site is | Burgess Creek | Receiving Environment Monitoring Program | situated in an ephemeral section of the Creek, which only contains surface water during and | immediately following rainfall, leading to an absence of water for most of the year, making it | difficult to collect water quality samples. Ongoing surface water monitoring above B3 poses | a significant challenge that may prove difficult to address. The impact of decreased surface | water flows, resulting from climatic variability, will be more pronounced in the West branch | above B3. This is because historical activities, such as residential and waste disposal | practices, have disrupted the creek's natural hydrology and soil composition. In contrast, the | hydrology and natural state of the East branch within the Noosa National Park have been | preserved, resulting in surface water remaining present throughout the year. | In 2021, the western section of Burgess Creek was primarily composed of treated wastewater | releases from the Noosa STP, as almost all the flow within this section was attributed to this | source. The Sampling Officers currently use subjective estimation methods to determine the | water flow within Burgess Creek, although this approach does not provide a quantitative | measurement, it is known from historical data that monitoring site B8 does not complete all 12 | sampling events. In 2021, flow was observed during only 3 of the 12 sampling events, | indicating that the western branch of Burgess Creek would have experienced few flow events | without the presence of Noosa STP treated wastewater releases. Unlike discontinued | monitoring site B4, monitoring site B8 is not affected by siltation and overgrown nature of the | channel. B8 is situated on a significant waterway that originates from the Melaleuca Forest | community, and experiences occasional waterlogging, which can impact the flow and quality | of water within the channel. | The results indicate that water stagnation may have occurred at B8 due to the low or no water | flow for a significant portion of the year. This is evidenced by the higher ammonia | concentrations observed at B8 compared to the other sites within the Catchment, where | ammonia concentrations remained consistent. The observed increase in ammonia | concentrations at B8 can be attributed to the lack of turbulence, which reduces volatilization | and increases the accumulation of metabolic waste and decomposition products, as per the | findings of Suter et al. (2021). | It is found that the B8 monitoring site above the Noosa STP Outfall continues to be the most | suitable location. However, the present parameters employed for estimating or measuring | water flow within the western branch are insufficient. The transient nature of the western | branch is a hindrance in obtaining accurate flow measurements. The absence of accurate flow | monitoring in this area is posing difficulties in ensuring consistency with the strategy | implemented two decades ago and coping with natural climate drivers and changes in rainfall | Burgess Creek | Receiving Environment Monitoring Program | patterns. Further research is necessary to establish dependable approaches to assess water | flow within this region. | The last detailed assessment of the impacts of the Noosa STP on Burgess Creek remains | consistent with the previous year's Burgess Creek Receiving Environment Monitoring Program | Annual Assessment and Review (2021) and was conducted in 2004. This modelling used the | only known measured flow rate within Burgess Creek and used flow data collected at the | nearby Teewah Creek. The principal issues of existing and historical land use remain largely | unchanged, but the increasingly variable rainfall events and intensity of these events may | have different consequences than originally assessed. Coupled with the Noosa STP | approaching the designed capacity and design life of the asset, reassessment of the current | disposal strategy into Burgess is recommended. Particular attention is recommended around | natural and sewage treatment flows within the western branch of Burgess Creek with the | changing climatic patterns to ensure the strategy of minimisation and disposal remains | unchanged from the original decisions. | A review of spatial variability of average concentrations of water quality parameters within | Burgess Creek showed that the Noosa STP outfall was not the sole influence on water quality | parameters, most notably microbiological indicators (E.coli, faecal coliforms and enterococci). | Microbiological indicators at Site B3, immediately downstream of the treated wastewater | discharge pipe, remain below upstream values represented in B8 and B2. Conversely, the | highest concentrations are represented at B1 and SW3, furthest from the outfall. Typically, | with good quality treated wastewater and the creek having a high flow rate and good mixing, | the microbiological indicators should decrease with distance downstream due to dilution and | natural degradati