Technical Advisory Framework
Read the Technical Advisory Framework
Supporting Citizen Science
Technical Advisory Framework
Date: March 2025
Version: 1
2. Collaborative Monitoring Plans
3. Key principles for citizen science monitoring
Principle 1. Connect and collaborate
Principle 2. Build on and learn from existing monitoring
Principle 4. Develop a well-designed monitoring plan:
Principle 5. Follow quality control measures
Principle 6. Interpret and understand your findings
Principle 7. Communicate and share outcomes
Principle 8. Apply outputs to actions
Would you like to find out more about us or your environment?
The Environment Agency - GOV.UK(External link) (EA) is working with partners to develop tools, guidance and frameworks to support a standardised and connected approach to citizen science monitoring of the water environment.
This technical advisory framework, co-produced with the citizen science community has been designed to help individuals and groups to develop new, or review existing, citizen science monitoring programmes to meet their needs.
Version 1 of the framework focuses primarily on water quality and quantity, with an emphasis on freshwater (rivers and lakes) with additional information about estuarine and coastal waters to follow in version 2 expected in 2025.
What is the purpose of citizen science
Citizen science involves public participation and collaboration in all aspects of scientific research. It can be adapted and applied to diverse situations and disciplines, encompassing a wide range of approaches:
● Across different scales: from national continuous projects to focused local studies, or short bursts of activity to those repeated over a longer timescale.
● With differing skills requirements: ranging from those requiring no prior knowledge or training, to those requiring training and specialist knowledge.
● To achieve a wide range of aims: from measuring environmental and societal change, spatial mapping of objects and features, and many more.
Why is this framework needed?
No single organisation is responsible for collecting all the data needed to protect and manage the environment effectively. Telling an engaging, informative story that drives action relies on interweaving multiple strands of data and observations.
Citizen science offers a valuable opportunity for the Environment Agency (EA) to engage communities in scientific research, data collection, and local decision-making, building stronger relationships with communities and stakeholders through shared goals.
Participation in citizen science, and public interest in monitoring and improving the local environment is increasing. This groundswell of support is encouraging and inspiring, however with limited resources, we cannot support all initiatives or use all data collected by citizen scientists, we need to prioritise on a case-by-case basis.
This framework, and our advisory role with other stakeholders, aims to support well-designed citizen science monitoring initiatives with embedded quality assurance measures to allow the Environment Agency and others to use the data and information to understand the environment and assess the actions needed to improve it.
How to use this framework
This framework is divided into eight key principles which form a structured approach to guide volunteers, coordinators, and stakeholders through the process of planning, conducting, and utilising citizen science monitoring projects. It outlines the steps needed to ensure that the data collected is consistent, high-quality, and meaningful.
We recommend working through the key principles in this framework with your catchment partnership, citizen science community, or other local partners to benefit from their collective knowledge, experience, and skills. This framework should be used as a monitoring pathway and continuously revisited and reviewed.
By following these principles, and using the linked guidance and information within, we hope that citizen science initiatives will become more meaningful and useful for you and others.
Given the widening motivations for participating in citizen science, we are not recommending specific equipment, methodologies, or initiatives within this framework.
We will update this framework over time to reflect changes in our understanding, priorities and advances in monitoring technology and methodology, and will continue to engage with the citizen science community as updates are prepared and published.
Where to start - understanding the purpose and the outcome
The first four principles in this framework have been designed to help you to plan the monitoring you will be carrying out.
Before you begin planning, you should spend some time thinking about what it is that you want to achieve by participating in citizen science.
For example:
● To participate in a one-off activity which requires no training or previous knowledge.
● An opportunity to meet new people and be part of a community
● An opportunity to learn skills and commit to getting involved more regularly.
● Or if you are already involved, perhaps you are interested in further developing your skills.
Or if you are a volunteer coordinator, community group leader or other stakeholder planning on developing a citizen science initiative, consider what it is you plan to achieve through citizen science monitoring.
For example:
● What information you would like to collect?
● Why is this information needed?
● Is citizen science the right approach?
Once you establish what you want to achieve, you can work through the principles to plan an effective approach and develop a collaborative monitoring plan.
Additional information
The links listed below provide additional information which may support you in your planning:
● UK Environmental Observation Framework guide to citizen science(External link)
● UKCEH and SEPA- choosing and using citizen science(External link)
● Ten Principles of Citizen Science – European Citizen Science Association (ECSA)(External link)
● Check Clean Dry Protocol | Non-Native Species Secretariat(External link)
● Laboratory Plastics Case Study - Preventing Plastic Pollution(External link)
2. Collaborative Monitoring Plans
The eight principles of this framework have been developed and informed by existing guidance on environmental monitoring and planning which you can access through the links below:
● Monitoring Guidance | the River Restoration Centre(External link)
● UKEOF unifying principles for environmental monitoring | UKEOF(External link)
Each of the principles will provide support and direction to help you to develop a well- structured collaborative monitoring plan which has consistent, reliable, and robust monitoring, while remaining accessible and useful to volunteers and partners of varying skill levels.
The Catchment System Thinking Cooperative (CaSTCo)(External link) have produced clear guidance on collaborative monitoring plans and templates for you to use which you can access through this link: Collaborative monitoring planning Archives - CaSTCo(External link)
Guidance from CaSTCo and the eight principles of this framework will encourage you to consider:
● Why monitoring and data collection is needed.
● Where to monitor
● When to monitor
● How to monitor
● How to use your data to maximise impact.
3. Key principles for citizen science monitoring
What are the principles & why is it important to consider them
By following these principles, you'll ensure that your monitoring efforts are not only scientifically robust but also meaningful and impactful for your community and the broader scientific community.
Each principle in this pathway helps you to navigate the complexities of citizen science monitoring, from connecting with local partners to sharing your findings in accessible and engaging ways.
The 8 principles are:
1. Connect and collaborate: Work in partnership to achieve common goals.
2. Build on and learn from existing monitoring: Explore what, where and how others are monitoring in your local area to inform your monitoring plan.
3. Define the purpose: Clearly define the objectives and goals of your individual participation, planned citizen science initiative or monitoring programme.
4. Develop a well-designed monitoring plan: Set appropriate level and accuracy of monitoring design to meet project objectives.
5. Follow quality control measures: Ensure all processes meet established standards of quality and include evidence of training, calibration and validation steps in the monitoring plan.
6. Interpret and understand your findings: Explore the interactions between parameters measured to understand the health of your local waterbody.
7. Communicate and share outcomes: Maximise the impact of your results by sharing outcomes in accessible, FAIR and visual way with relevant stakeholders.
8. Apply outputs to actions: Use the results to inform action and environmental improvement.
Principle 1. Connect and collaborate
Work in partnership to achieve common goals
Why is this important?
Citizen science involves collaboration with and learning from others, including local environmental groups, catchment partnerships, and other citizen science projects.
Identifying and connecting with local stakeholders will help you to identify shared objectives and provide opportunities to work together for cooperative monitoring.
This may also help you identify locations or environmental pressures that would be more beneficial to monitor than others.
Citizen science initiatives should be led by the organisation that is best suited to deliver citizen science. This isn’t always the EA, although we often provide support through funding and technical expertise we will always aim to work with and through our partners.
How can I find out more?
Find out which catchment you are in by using the England | Catchment Data Explorer,(External link) and get in contact with your local catchment partnership by using the links below:
● Home – Catchment Based Approach (External link) (CABA)(External link) The Catchment-Based Approach (CABA), is an inclusive, civil society-led initiative that works in partnership with Government, Local Authorities, Water Companies, businesses and more, to maximise the natural value of our environment.
● Catchment Partnership Pages | (External link) Catchment Data Explorer(External link). The Catchment Partnership Pages have been created in collaboration by catchment partnerships. These pages reflect the vision of the partnership, the challenges in the catchment as partnerships see them, the successes they have delivered during the previous cycle, their plans for partnership development over this cycle and some priority actions and measures.
You can also contact your local university to find out about current and future projects
and opportunities to collaborate.
Principle 2. Build on and learn from existing monitoring
Explore what, where and how others are monitoring in your local area to inform your monitoring plan
Why is this important?
Finding out where and what others monitor can help you to understand what data is already available that you can benefit from, as well as identify gaps or opportunities to complement these data and prioritise monitoring methods and locations.
How can I find out more?
We recommend getting in touch with your local catchment partnership to find out what citizen science and environmental monitoring may already be happening in your local area.
Find out which catchment you are in by using the England | Catchment Data Explorer,(External link) and get in contact with your local catchment partnership by using the links below:
● Home – Catchment Based Approach (External link) (CABA)(External link)
Table 1 in the Appendix provides some examples of existing citizen science initiatives that you may want to consider.
You can also use Environment Agency data to support your monitoring plan by:
● Informing site selection
● Providing reference conditions
● Providing complementary and background data
● Providing baseline information
Further information on what the Environment Agency monitors, tools to access and interpret this data, and links to useful plans and reports are outlined in Table 2 in the appendix.
Explore what and where the Environment Agency monitor
The Environment Agency’s environmental monitoring data is open to the public, and accessible through the Department for Environment Food & Rural Affairs (Defra) data portal and signposted through the Environment Agency’s Water Hub. Site locations and results can be visualised on the River Basin Management Plan maps.
The following links can help you to explore the Environment Agency’s data:
● Defra Data Services Platform (External link)the Data Services Platform is run by Defra to make environmental data openly available to a wide range of users.
● Water Data Explorer | Engage Environment Agency a tool for engaging with and exploring water quality and environmental data provided by the Environment Agency.
● River Basin Management Plan: maps(External link) these maps display information updated for the River Basin Management Plans.
Data within each explorer is also accessible through Application Programming Interface (APIs), programming language which provides access to the raw data visualised in these apps. Watch this YouTube video to find out more: What is an API?(External link)
The River Chess Smarter Water Catchment project has used a series of complementary monitoring techniques to understand the issues and monitor any actions to restore this chalk stream catchment. This has involved partners from statutory agencies, non- governmental organisations, water companies and academic institutions, with an emphasis on working with communities and citizen science throughout.
Monitoring has included maintaining a set of continuous monitoring sondes measuring water quality, Mud Spotter(External link) surveys in wet weather alongside sediment fingerprinting to trace the sources of sediment, testing of emerging chemicals, before and after restoration habitat surveys using MoRPh(External link), flow monitoring, water vole populations as well as extensive Riverfly surveys.
Using a combination of techniques from both citizen scientists and science professionals has enabled a greater depth of understanding both spatially and over time, increasing confidence in where investment is needed to improve river condition.
This has been run alongside the 'Tracking the Impact'(External link) project which focuses on the
terrestrial species living in this catchment: breeding birds, butterflies, and plants. Recognising the importance of the surrounding landscape as part of the whole catchment ecosystem.
How are we using this information:
● Volunteer flow monitoring is plugged into our database and directly used by hydrometry teams to fill in spatial and temporal gaps.
● Geomorphology teams are advising on sediment fingerprinting and feeding into restoration plans and fisheries work.
● Riverfly data is providing greater understanding of where populations of invertebrates are across catchments (including invasives). The discovery of the winterbourne stonefly by Riverfly volunteers at the top of the Chess has driven Environment Agency intermittent stream monitoring programme across the chalk.
The links below to the website and YouTube video cast study provide more information:
• Citizen Science | R Chess catchment | Smarter Water Catchment(External link)
• Chiltern Chalk Stream Project | The Ripple Effect(External link)
Clearly define the objectives and goals of your individual participation, planned citizen science initiative or monitoring programme
Why is this important?
To maximise the impact of your monitoring, you should be outcome driven. Setting clear and realistic objectives, agreed by all those involved, will help direct your monitoring plan and ensure data collected is relevant and impactful.
When considering the intended outcomes for your project consider:
● The skills, motivation, accessibility needs, and level of commitment of volunteers/ local community
● Recruitment, recognition and retention of volunteers.
● Realistic timescales to allow for contingency planning and meet length and restrictions of funding
You will need to consider the balance between time and effort required. For example, if you are planning an intense monitoring programme over a short period of time this would be an example of a blitz with short time frame and low effort, compared to high level of investment in monitoring equipment and training such as the River Chess in Box 1 would be longer time frame and high effort.
In collaboration with CaSTCo and other environmental non-government organisations (eNGOs), we have developed a 4-tier approach to help categorise and identify which methods and initiatives may be most suitable to meet your needs and project objectives, This approach encourages you to consider the level of investment required in cost, time and skills development, and balance this with the differing levels of resulting data quality and quantity.
Deciding on an appropriate tier at the start of project planning will help inform your monitoring plan and provide clarity when working through the rest of this framework.
Data and information from each tier are extremely valuable and useful, with each tier contributing data to our wider understanding of environmental health, and important information for stakeholders involved in catchment planning.
Further information on how we define each tier and examples across citizen science for bathing water, water quality, biodiversity and water quantity monitoring are outlined in Table 3 in the Appendix.
How can I find out more
Setting your primary purpose:
● CaSTCo guidance can help define the purpose which you can access through this link: Guidance: defining your primary monitoring purpose - CaSTCo(External link) and this link: Defining your purpose - CaSTCo(External link)
Defining clear objectives:
● JNCC guidance can help with setting biodiversity monitoring objectives which can be accessed through this link: Setting biodiversity monitoring objectives | JNCC Resource Hub(External link)
Outlining the intended impact of your outcomes, or planned use of data and information collected:
● MICS (Measuring the Impact of Citizen Science) information can help with setting outcomes. You can access through this link: Measuring Impact of Citizen Science - Indicators(External link)
● CaSTCo guidance can support you with outcomes: Making a difference - CaSTCo(External link)
If your plan is to conduct a blitz such as The Big River Watch(External link), hosted but The Rivers Trust, the following guidance from CaSTCo will help you plan:
● Guidance: Designing a Water Blitz - CaSTCo(External link)
● RiverBlitz review(External link)- Ribble Rivers Trust
The River Wharfe in Yorkshire has an active and engaged citizen science community which works collaboratively with the EA, catchment partners and academic institutes and operates under the ‘iWharfe’ project banner – largely coordinated by Professor Rick Batterbee & Yorks Dales Rivers Trust (YDRT under the Dales to Vales River Network Catchment Partnership).
Ilkley was designated a bathing water site in Dec 2020 and was the first river site in England designated.
Collaborative monitoring was carried out by the Environment Agency and iWharfe citizen scientists to characterise the waterbody from source to confluence and better understand the bacterial loading from various tributaries in the catchment.
The Environment Agency provided technical programme design, logistical support for sample transport, lab analysis of samples & data interpretation. YDRT, recruited, organised & managed citizen scientists’ involvement. Yorkshire Water funded YDRT staff time to undertake citizen science volunteer recruitment and management.
This involved intensive survey across one day to collect samples across the catchment. This level of sampling effort could not be achieved using just Environment Agency resource.
How have we used this data:
Samples were sent to the laboratory for analysis and results helped to direct efforts upstream. This case study demonstrates how working collaboratively with different catchment partners can produce these high spatial intensive data sets. You can find more information by clicking the links below:
● Working towards a cleaner Wharfe – a closer look at water quality testing at Ilkley’s (External link) bathing water – Creating a better place(External link)
● The iWharfe Project, a Case Study - A CaSTCo Webinar, 21st November 2023(External link)
Principle 4. Develop a well-designed monitoring plan:
Set appropriate level and accuracy of monitoring design to meet project objectives.
Why is this important?
Once you have agreed on the purpose and objectives of your project, it is essential that you work collectively with your citizen science and monitoring community to set a clear plan of where, when, and how you carry out your monitoring to achieve these objectives.
Your monitoring plan should also include information on how you plan to share your findings to maximise impact and use (see principle 7- communicate and share outcomes). This will form the basis of your collaborative monitoring plan.
What you should consider: where to sample
When devising the number and location of your sampling locations for your monitoring strategy, you should consider:
Volunteer needs:
● Locations should be safe and accessible for all citizen scientists
● Time, commitment and training needs of citizen scientists
Existing monitoring sites:
● Can additional data be used to supplement your proposed monitoring or inform your sampling points? (see principle 2- build on and learn from existing monitoring)
Sample location:
● You must have permission to access site
● The sites should be representative and appropriate to meet your project objectives.
● Some initiatives will require liaison with the citizen science coordinator or Environment Agency contact to set sampling locations and thresholds for monitoring. One example is Riverfly, you can find more by clicking on this link: Key Documents — The Riverfly Partnership(External link)
● The Environment Agency recommend sampling from 10 river widths downstream of a suspected source of pollution to avoid the mixing zone and collect a representative sample.
● CaSTCo have provided additional information that you can access through this link: CaSTCo- where will you collect data(External link)
Health and safety:
● Setting and following health and safety guidance, which includes volunteer training, safe and legal access to sampling location, and a record of compliance is essential.
● Volunteer management and health and safety compliance should be managed and delivered through the lead partner organisation who hold the duty of care for their volunteers.
● This link will take you to some guidance from CaSTCo: See example health and safety guidance from CaSTCo(External link)
● On the exceptional occasion where volunteer citizen scientists are recruited and working directly with the Environment Agency, they will be required to follow Environment Agency guidance on working with volunteers which will include water safety training and full Personal Protective Equipment (PPE) provision.
What you should consider: When and How Often to monitor
When setting the timing and frequency of your monitoring you should consider:
Volunteer needs:
● Time, commitment and training needs of citizen scientists
Project budget:
● Balance how long and how often to sample with the cost of monitoring and analysing the data to meet your monitoring needs.
Environmental conditions:
● River height and flood warnings
● Weather conditions
● Tidal cycle
● Season
Variation in environmental conditions may influence the physical, chemical, and biological characteristics of the waterbody, as well as when the conditions are safe to sample. For example, invertebrate diversity, appearance and extent of ephemeral and intermittent streams, and freshwater sources and springs.
This guidance from CaSTCo may support you to plan your monitoring: CaSTCo- when will you collect data(External link)
Seasonal sensitive areas:
Be aware of potential disturbance to wildlife, including fish which may be more significant at different times of the year. The links below will take you to our blogs on closed fishing periods and a user’s guide to being river and lake friendly:
● Respecting the coarse fish close season and why we enforce it(External link)
● A user’s guide to being river and lake friendly(External link)
Bathing waters:
If your monitoring plan involves sampling bathing waters, the blog and YouTube video linked below explain how the Environment Agency monitors and tests bathing waters, as well as consult the bathing water profiles:
● How the Environment Agency monitors and tests bathing water quality(External link) How does the Environment Agency check bathing water quality?(External link)
● Bathing water quality profiles(External link)
How to sample
When considering which methods to use, these should be appropriate for the purpose of your monitoring. You should also consider the tiers of methods outlined in Table 3 in the Appendix, and the associated quality assurance expectations that are associated with different tiers.
For example:
● Tier 0 may include observations, including photographs and anecdotal information which can be useful to provide additional information in areas we do not currently sample and requires no specific training or equipment.
● Tier 2 or 3 monitoring programmes may include varying levels of quality assurance from calibrated and quality-controlled field samples to quality controlled laboratory analysed data from bathing waters. Depending on the level of quality control these data may complement Environment Agency data, providing valuable information in locations and times that are outside of our own monitoring. This can be invaluable to indicate variation in water quality over space and time but will require a higher investment from citizen science in equipment and quality control to meet the standards expected for tier 2 or 3.
We recommend:
● Using existing methodology where possible (see example initiatives in Table 1) which will have quality control in place.
● Following a method audit process for any proposed new methods or kit. Method audits have been carried out to compare selected methods for biological, water quality, physical and soil monitoring through CaSTCo, as well as a framework to follow when carrying out a method audit.
● Looking at guidance from CaSTCo: Overview: Method audit process - CaSTCo(External link)
Further information on the parameters commonly monitored including water chemistry (phosphorus and ammonia) can be found by using the links below:
● Overview: Phosphorus - CaSTCo(External link)
● Ammoniacal nitrogen fact sheet
● Methods list and categories - CaSTCo(External link)
Hello Lamp Post invites local residents and visitors at selected sites across the country to chat to their local beach, river or lake using the Hello Lamp Post artificial intelligence platform.
Those taking part have been able to contribute to citizen science by sharing their own observations from these sites.
The information from these conversations has helped the Environment Agency to understand who visits these sites and how this varies over time. It has also provided the Environment Agency with information on water quality observations and any signs of pollution.
You can find out more by reading our blog Supporting Citizen Science- Hello Lamp Post Pilot
In the West Midlands, the Environment Agency are working with Severn Rivers Trust (lead partners), Severn Trent Water, The Rivers Trust, and volunteers to monitor bathing water quality and river health across the Teme catchment as part of CaSTCo.
With a newly designated bathing water at Ludlow, the group are testing different methodologies to monitor water quality and bacteria across the catchment which will provide useful information on potential sources of pollution and reliability of methods and kit.
More information can be found through clicking on the links below:
● Severn: Citizen science bacteria testing - CaSTCo(External link)
● CaSTCo Water blitz comparing bacteria and chemistry methods in the Severn(External link)
● CaSTCo Teme data visualisation tool(External link) created for open access to data
Principle 5. Follow quality control measures
Ensure all processes meet established standards of quality and include evidence of training, calibration and validation steps in the monitoring plan
Why is this important?
Putting measures in place to ensure the methods used for monitoring, data entry and data analysis meet a set of standards will improve the quality of your data and provide you with confidence in your findings. Demonstrating to others that your data has followed a quality assurance process will also improve the trustworthiness and value of your data and information.
The level of quality assurance your monitoring plan follows can be cross referenced to the tiered approach (see Principle 3- Define the Purpose and Table 3 in the Appendix). This will help stakeholders assess where the data and information collected from each tier can be used to maximise its impact, ensuring the right data is used for the right purpose.
Quality assurance
This is the process you will apply to check the quality, accuracy, reliability, and repeatability of methods used and data produced. This helps provide confidence in data, increasing the weight it can be given in weight of evidence and enabling it to be used for a greater range of purposes.
It should include:
● Process for training new volunteers and refresher training for existing volunteers
● Comparison and cross reference of equipment
● Steps taken to check, maintain and calibrate equipment and reagents used
● Steps to check and clean your data and remove errors
This handbook produced by the US Environmental Protection Agency is a useful reference: Quality Assurance Handbook and Toolkit (External link) for Participatory Science Projects | US (External link) EPA(External link)
Quality control
Collecting good quality data is the backbone of any data collection programme. From the start of your project consider the quality of your data.
Basic visualisation of your data as a graph or on a map, can help you to spot errors that might otherwise be difficult to detect such as errors in site location due to mistakes when entering grid references, or anomalous results that might need to be repeated.
For data to be quality assured, choosing the appropriate and suitable monitoring equipment is essential.
Below are some tips to consider when purchasing equipment:
● Does the kit/instrument have any quality certification? This is especially
● important for test kits
● What is the principle of operation? This must be acceptable to one or more of the accreditation bodies in the EU or North America.
● Are there reagents used? If so, are they safe for non-technical staff or
● children to handle?
● How often will it need calibrating? What is the frequency of maintenance?
● What are the lower and upper limits of detection? For example, many Phosphorus test kits do not detect at the lower limits required.
● What is the accuracy in terms of precision?
● What is the resolution? Some manufacturers state very tight resolution, but this is meaningless if accuracy is not good.
● Is the instrument robust and suitable for field or laboratory use? Will the unit be cost effective?
This best practice guidance produced by the Marine Biological Association is a useful reference: DASSH - Best Practices(External link)
Consistency in recording your data
Be consistent when recording your data- over time and across different sites. This will help reduce transcription errors.
● Do not leave blanks- create a consistent format to identify whether a sample was attempted but no data collected.
● For example, adding a separate tick box for no sample possible, with a notes field to explain why, is good practice. A second tick box for site dry might also be worthwhile in drought prone areas.
● Do not use zeros to represent no sample taken, zeros should only be used to represent genuine data readings.
● Check whether your zeros are genuine data. Understanding the lower limits of your equipment will help to determine this.
● For example, check the threshold limit of your equipment, some maybe accurate to ± 0.04 (or 5% for higher readings), so a zero is not zero but ≤0.04.
Site locations:
Be consistent when naming. If a site location changes, use a new site name. If a site location name is updated with more accurate information, please change all instances of that location.
If using apps to record data, these will often give the phone’s location and potentially create a new point for each sample. If this is happening, consider how your survey is set up to avoid multiple site references for the same site or repeated visits of the same location or create exact site names to collate points at each site and give them all the same National Grid Reference.
Site ‘name’:
● Must be unique and in a consistent format.
● Don’t mix A, B, C with 1, 2, 3 and/or 1A, 1B, 1C.
If using site names that give location information, build plenty of capacity into your system. For example, rather than starting 1, 2, 3 as you go downstream then adding the first tributary at 11 consider:
● 0001 to 0099 as you go downstream
● 0100 to 0199 for your first tributary etc.
Site names should not include special characters, punctuation, or brackets as these can cause issues with data upload.
Recording your data digitally
Where possible record data digitally. If using paper forms, ensure data is uploaded to a digital format and this is checked for errors.
Benefits of recording digitally:
● Apps may have inbuilt error checkers to help avoid errors in your data
● Smart phones have inbuilt GPS with an average accuracy of <50m
Disadvantages of recording data digitally:
● Requires all users to have access to smart device or IT
● Risk of no phone/Wi-Fi signal or reduced battery power
● Requires a level of IT literacy and capability
The accuracy of data from trained citizen scientists using digital photometers on the Lark and Wensum was investigated as part of the CaSTCo demonstration catchment activities(External link).
As part of this process a pilot quality assurance process was developed to check consistency in volunteer data accuracy. Colourless phosphate and ammonia standard solutions were provided by The Rivers Trust from a commercial partner and divided into labelled tubes indicating the type of solution but not its concentration. Citizen scientists from the Wensum, Lark, Cam, and Waveney tested these standard control samples following their standard testing protocol and results returned to a Quality Assurance lead. A sub sample of each standard was sent to the Environment Agency laboratory for verification.
The results demonstrated that handheld photometer phosphate testing remained broadly accurate, and ammoniacal nitrogen testing still clearly indicates if levels are potentially acutely toxic. Handheld photometer battery level affected accuracy and there was some variation due to temperature in transport and storage because low temperatures result in slower reaction rates. The volunteers who didn’t achieve expected results were approached to check their kit and technique.
This work highlighted the following which the citizen science groups have now written into an updated quality assurance process:
● Importance of changing the batteries in handheld photometers on a regular basis
● Testing technique, which could vary for ammonia testing where the manual doesn’t define how reagents should be mixed into the sample
● Temperature needs to be standardised as much as possible
Principle 6. Interpret and understand your findings
Explore the interactions between parameters measured to understand the health of your local waterbody
Why is this important?
It is important to recognise that rivers, estuaries, and coastal waters vary naturally in space and time, and parameters monitored in and around your waterbody do not act in isolation but will interact and affect each other.
By collating and analysing the different parameters you have sampled as well as incorporating data from others will help to identify patterns and trends in your data and provide a broader understanding of the health of your waterbody.
Simple visual summaries such as graphs will help to see how your data varies and interacts with each other. Looking for patterns over time and space by mapping or cross referencing to site locations will allow comparison between and within sites and identify spatial changes.
However, it is important to recognise that each waterbody and site location will react and respond individually due to the different site specific physical, ecological, and chemical characteristics, so be cautious when comparing data from one location to another.
How can I find out more?
Freshwater- Rivers and lakes
The links below provide reference guidance on how to understand different river types and interpret Environment Agency data to help you understand the health of your local waterbody:
● River Typology locations: River Basin Management Plan: maps(External link)
● River type for Water Framework Directive (WFD) classification
● General water quality parameter interactions (separate pdf of this table will be uploaded as supplementary info)
● Template for site specific water quality interactions- to follow
● CaBA/CaSTCo- how to calculate site specific standards
Information on long-term lake monitoring carried out through UKCEH and information on ecological classification of lakes using aquatic plants can be found by following the links below:
● Long-term lakes monitoring | UK Centre for Ecology & Hydrology(External link)
● The ecological classification of UK lakes using aquatic macrophytes -(External link)
Marine
Information to support coastal monitoring and data interpretation will follow in future versions. Below are details on current monitoring methods for coastal and transitional waters from the Water Framework UK TAG:
● Transitional and Coastal Waters - Saltmarsh | wfd uktag(External link)
● Coastal Waters – Rocky Shore Macroalgae | wfd uktag(External link)
Principle 7. Communicate and share outcomes
Maximise the impact of your results by sharing outcomes in accessible, FAIR and visual ways with stakeholders
Why is this important?
Sharing your data can help to maximise the impact and reach of your project. We recommend you follow an ‘open by default’ approach where possible and consider options to share your data both as raw data and in a format which enables others to easily visualise it. This will help other stakeholders to access your data as well as gain insights and maximise its value.
We recommend:
● Ensuring your data is findable by all the partners who are involved in the management of your monitoring:
● Make your local Catchment Partnership aware of what data you are collecting and where.
You can follow the FAIR (Findable, Accessible, Interoperable and Reusable) data principles to help you do this. FAIR Principles - GO FAIR(External link)
Findable
The first step in (re)using data is to find it. Metadata and data should be easy to find for both humans and computers.
It is good practice to clearly communicate the following information along with your data. This is termed metadata which provides the user with context or additional information about your data:
● How your data was collected (where, how often, by who)
● Which methods and equipment were used for each data point.
● What quality control processes are in place- see Principle 5- Follow quality control measures).
● Principles of good data governance- (External link) CaSTCo(External link)
● Storing your data on a platform which has an API, this is a quick way to making your data FAIRer. Watch this YouTube video to find out more: What is an API?(External link)
Accessible
Once the user finds the required data, the user needs to know how it can be accessed, possibly including authentication and authorisation.
● If your data is stored on a website which require a log-on, your data is only accessible to those with log-on credentials- consider whether you want to restrict access to your data
Following an ‘Open by Default’ approach to sharing data and making your data accessible to all will maximise the likelihood of its use, and the insights gained from a wider range of stakeholders, meaning environmental action can be taken in the right places.
At the Environment Agency, we follow an Open by Default approach to sharing data and publish the vast extent of our data under an Open Government Licence.(External link) You can find out more about this through clicking this link: Environment Agency data (External link) licensing – simpler, easier, faster(External link).
You can find out more about Open data by clicking on the below links:
● Open data in the water industry - Ofwat(External link)
● What is 'open data' and why should we (External link) care? | The ODI(External link)
Interoperable
The data usually needs to be integrated with other data. In addition, the data needs to interoperate with applications or workflows for analysis, storage, and processing.
Reusable
The ultimate goal of FAIR is to optimise the reuse of data. To achieve this, metadata and data should be well-described so that they can be replicated and/or combined in different settings.
Visualising your data can help others to understand what data you have collected and where, potentially increasing the impact of your data.
Combining your data alongside other open access data including from other citizen science groups and the Environment Agency can be helpful to provide a more comprehensive picture.
Please note, if your data is only shared in graphs or maps without access to the data behind these visuals, this is not considered reusable.
Personal data
Personal data is subject to legal protection such as the General Data Protection Regulations (GDPR) and needs to be stored securely and not publicly accessible. It is your responsibility to follow the government’s regulations with respect to data sharing and personal data. More information can be found at the Information Commissioners office UK GDPR guidance and resources | ICO(External link)
You may also have agreements with landowners or decide that publishing certain results publicly without context could result in reputational risks to yourselves or others. Your system should enable access to be restricted where necessary, whilst remaining Open by Default and FAIR.
Various Citizen Science groups within the Wye catchment have formed the Wye Alliance. The Wye Alliance is a collection of groups that follow aligned methodologies when collecting data within the catchment. This collaborative approach helps them combine data, expertise and decision making. Data collected is uploaded to the EPICOLLECT database as one data set, rather than individual data sets.
A consistent approach for all Citizen Science groups across the catchment improves accuracy and helps the Environment Agency gain a better understanding of the environmental complexities of the catchment.
● For more information on how the Environment Agency are working with the Wye Alliance visit: Citizen Science in the Wye | Engage Environment Agency
● To hear more about the WyeViz tool watch this short YouTube video: Introduction to WyeViz (the Wye Alliance Citizen Science dashboard)(External link)
Principle 8. Apply outputs to actions
Use the results to inform action and environmental improvement
Why is this important?
As part of your monitoring, what you will do with your data and how you can use your findings to inform action is essential.
Your results and findings may be important to inform your future monitoring plan, entering back into the planning pathway. Outcomes may inform future sampling locations or additional methods to consider to further improve understanding.
Others will also be interested in your data, this could include the EA, water companies and other water stakeholders. This link provides more information from CaSTCo on making a difference: Making a difference - CaSTCo(External link)
Your data along with data from others will contribute to collective evidence bases and a more comprehensive picture of environmental health to help inform and prioritise action and decision making.
The tiered approach enables partners to understand how the data has been collected and the quality control steps taken to improve data quality. Partners can then use this approach to help assess where the data and information collected from each tier can be used to maximise its impact, this ensures the right data is used for the right purpose.
How is the Environment Agency currently using citizen science data?
To improve certainty in our decision making
● For example in our Weight of Evidence Eutrophication tool- see the following webinar for more information: Environment(External link) Agency Eutrophication Weight of Evidence(External link) Approach(External link)
● Working towards a cleaner Wharfe – a (External link) closer look at water quality testing at (External link) Ilkley’s bathing water(External link)
To provide additional catchment intelligence
● For example, provide additional information across space and time- see iWharfe example in Box 2.
To support investigations
● For example, see the CaSTCo case study on the River Tat, East Anglia: Citizen (External link) science helps resolve pollution issue - (External link) CaSTCo(External link)
You can find more information about how we are using citizen science data on our Water Hub page using this link: Citizen Science - working together! | Engage Environment Agency
Acknowledgements
This framework was developed through collaboration - with thanks to The Rivers Trust(External link) and CaSTCo partners(External link), The Riverfly Partnership(External link), Earthwatch(External link), SmartRivers(External link), and all the citizen scientists and water stakeholders that offered advice and suggestions.
If you have any feedback or suggestions on the Technical Advisory Framework you can fill out our short survey: Technical Advisory Framework feedback(External link)
Table 1. Examples of freshwater and coastal citizen science monitoring programmes and national monitoring ‘blitzes’- intense monitoring across a short period of time, in England:
Monitoring Initiative | Lead organisation | Water type | Duration of monitoring | Link to source |
Riverfly Monitoring Initiative (RMI) | Riverfly partnership | Freshwater | Regular monitoring- weekly/monthly | |
SmartRivers | Wildfish | Freshwater | Spring and Autumn | SmartRivers | Scientifically Robust Citizen Science | Wildfish(External link) |
Freshwater Watch | Earthwatch | Freshwater | Regular monitoring- weekly/monthly | |
Angling Trust Water Quality Monitoring Network | Angling Trust | Freshwater | Regular monitoring- weekly/monthly | Epicollect5 - Water Quality Monitoring Network(External link) |
MoRPh Rivers | Modular River Survey | Freshwater Habitat | Occasional | |
Surfers Against Sewage- Recreational Water Quality | Surfers Against Sewage | Recreational Waters- Coastal and Inland | Regular monitoring- weekly/monthly | Citizen science results - Surfers Against Sewage • Data HQ(External link) |
Big Seaweed Search | Natural History Museum | Marine/Coastal | Occasional | |
Shoresearch | The Wildlife Trust | Marine/Coastal | Occasional | |
The Big River Watch | The Rivers Trust | Freshwater | Spring and Autumn Waterblitz over a weekend | The Big River Watch Data Dashboard | The Rivers Trust(External link) |
Great UK Waterblitz | Earthwatch | Freshwater | Spring and Autumn Waterblitz over a weekend | Great UK WaterBlitz Results | FreshWater Watch(External link) |
Table 1: Examples of freshwater and coastal citizen science initiatives.
Table 2. Examples of Open Access Environment Agency monitoring data, reports and plans.
Type of data | What it covers | How it can be viewed | Where to access this information | Parameters/indices measured or category of data available | Further information |
Macroinvertebrates, aquatic plants & fish data | Datasets of benthic macroinvertebrates, macrophytes (aquatic plants), and fish from surveys for river and tidal freshwaters. These include species lists, abundances, biotic indices and site data. | Datasets can be viewed online and/or bulk downloaded | Average Score Per Taxa (ASPT), Biological Monitoring Working Party (BMWP), Whalley, Hawkes Paisley & Trigg (WHPT), River Macrophyte Nutrient Index (RMNI), Individual Taxa records Rivers (uktag): Invertebrates(External link), macrophytes(External link), fish(External link) Lakes (uktag): Macrophytes(External link) | The different types of fish monitoring – Creating a better place(External link) Cardiff University Invertebrates Study(External link) Find out what we discovered on one of our freshwater plant surveys(External link) A day in the life – plant surveying on the River Mimram – Creating a better place(External link) | |
Hydrometric data | Dataset on river levels & flow, rainfall, groundwater and continuous water quality measurements (sondes). | Datasets can be viewed online and/or bulk downloaded | River level/ Groundwater level Daily mean river flow Daily rainfall Dissolved oxygen (% saturation) Long term daily flow records Temperature | Hydrology Data Explorer(External link) Making river, rainfall and groundwater data available(External link)
| |
River Habitat | Dataset on River Habitat Surveys which include data on the physical character and quality of river habitats across the UK. | Dataset must be downloaded to view the data | River Habitat Survey – Survey Details and Summary Results(External link) | Channel form Bankside vegetation Weirs/sluices, culverts, outfalls/intakes, dams, abstractions, hydroelectric power Habitat Quality Assessment (HQA) Habitat Modification Score (HMS) |
|
Water quality | Datasets of water quality measurements (physico-chemical & specific chemical pollutants ) taken from sampling points around the country and analysed in a laboratory. | Datasets can be viewed online and/or bulk downloaded | Explore water quality sites(External link) Download water quality data(External link)
| Ammonia, ammonium, dissolved oxygen saturation, electrical conductivity, orthophosphate, pH, water temperature, turbidity Metals, inorganic chemicals, organic chemicals. | How we test water quality(External link) Focus on Phosphorus in the Wye(External link)
|
Marine Plans | Find marine planning information for England, including data on marine licenses, environmental designations and policy information from regional marine plans. | Data and information can be viewed online | Marine licences Species data Designations and Protected Areas Aquaculture and essential fish habitat Ports, harbours, shipping and recreational areas | ||
Bathing Waters | Users can look up designated bathing water sites by name or location. Water quality is currently assessed by the Environment Agency from May to September, assessments measure current water quality are available, and at a number of sites daily pollution risk forecasts are issued. | Datasets can be viewed online and/or bulk downloaded | Escherichia coli or E. coli (EC) Intestinal enterococci (IE) | How does the Environment Agency check bathing water quality?(External link) | |
Geographic information | Interactive mapping providing geographic information about the natural environment from across government, covering rural, urban, coastal and marine environments across Great Britain. | Information is viewed online and can be downloaded either directly or through an external website | Land based and marine protected sites and designations Landscape classification Habitat classification Geology and soils Administrative boundaries Access Ordinance Survey background mapping | ||
Agricultural Land Environmental Risk and Opportunity Tool A.L.E.R.T.
| The Agricultural Land Environmental Risk and Opportunity Tool (ALERT) is an online Earth Observation mapping system produced by the Environment Agency in collaboration with Catchment Sensitive Farming (CSF). It enables partners to analyse the rural landscape and target local interventions to reduce pollution from agriculture. | Information is viewed online | Hydrology layers Land use and soil layers Slope threshold layers Topography data (LIDAR) layers Satellite imagery layers Urban layer and road layers
| ||
Catchment Data Explorer | Allow users to download information about the water environment used in river basin management plans. These include catchment Water Framework Directive classifications, associated objectives and measures. | Datasets can be viewed online and/or bulk downloaded | River Basin Management Plans Classifications Surface water chemical classifications Objectives and predicted outcomes Challenges Protected Areas Chemical Status
| Water body data update August 2023 – Creating a better place(External link) How to use Catchment Data Explorer(External link)
| |
Shoreline Management Plans | Shoreline Management Plans (SMPs) identify the most sustainable approach for managing the risk from coastal flooding and erosion over the short (0 to 20 years), medium (20 to 50 years) and long (50 to 100) term. Local authorities and the Environment Agency have led the development of these plans, working together in regional Coastal Groups.
| Action plans and reports can be downloaded | Evidence on how the shoreline has changed and may change in future Information on the risks from flooding and erosion to people and the developed, historic and natural environment within the SMP area |
Table 2: Open access EA monitoring data, reports and plans.
Table 3. Description and examples of tiers of citizen science monitoring. Activities within this table would generally be characterised against the different tiers as follows, there may be legitimate reasons why future activities wouldn’t neatly fit within a particular tier.
Tier | Description | Purpose | Examples of citizen science monitoring Bathing Water investigations | Examples of citizen science monitoring Water quality /Nutrient testing | Examples of citizen science monitoring Biodiversity monitoring | Examples of citizen science monitoring Water quantity |
0 | High-density, low-resolution data, limited, or no training, previous experience, or equipment required, flexible location and timing. Basic data quality control measures in place.
| Broad-scale water surveillance, capturing seasonal snapshots of water quality through mass sampling. Includes anecdotal records and monitoring in response to weather events. Useful for engagement and education.
| Observation of bather numbers and weather conditions. Observations of signs of pollution. Example: | Observation of water colour, signs of run-off, surface drainage, outfall pipes discharging of sediment in the water. Example: | Incidental or anecdotal records of wildlife on, in or around the water. Angling match-catch records, or records of invasive non-native species. Example: | Observations of barriers to river flow. Basic reporting of river flow as part of wider engagement initiatives such as The Big River Watch. Example: |
1 | Planned and delivered through a lead environmental Non-Government Organisation or academic partner, including volunteer recruitment and management. Basic monitoring equipment used with spatial or temporal focus. Training provided in person or online. | Short-term, high spatial scale or long-term regular catchment monitoring of pollution indicators and to identify environmental pressures. Collect high-density, moderate-resolution data to provide catchment intelligence and complement statutory monitoring.
| Monitoring indicators of pollution such as algae, nutrient levels (phosphate, ammonia, nitrates) using test strips or handheld colorimeters. With quality assurance and quality control in place. Monitoring of surface water outfall discharges and indicators of mis-connections in dry weather. Example: Severn: Citizen science bacteria testing - CaSTCo(External link) | Monitoring indicators of pollution such as colour/turbidity of water, pH. Nutrient testing (phosphate, ammonia, nitrates) using test strips or handheld colorimeters. With quality assurance and quality control in place. Example: | Invertebrate monitoring as part of a wider national initiative with volunteer training, Quality assurance and quality control in place. Can provide early warning signs of pollution and if acted on can prevent further deterioration. Example: | Flood wardens- acting as additional eyes on the ground to provide intelligence on flood risk and water levels. Reporting flow using widely reviewed apps with standardised flow categories. Example: |
2 | Monitoring plan is co-designed with multiple partners to meet monitoring standards, including methodology, sample location, and frequency. Training and equipment provided and approved by lead organisation, academic, stakeholder, or statutory bodies with high levels of quality assurance and control in place, including appropriate limits of detection. | To collect low volume of high-resolution data with significant investment in training, quality control, and assurance. Using high-quality equipment for direct monitoring of pollutants, environmental pressures or monitoring indicators of pollution using enhanced quality control. Data complements statutory monitoring. | This could include laboratory analysis of physico-chemical parameters as indicators of STW discharges. Example:
| Direct monitoring of nutrient levels using high specification equipment or equipment calibrated to statutory monitoring equipment. Data could be used as supporting evidence for Reasons for Not Achieving Good Status or to contribute to the Weight of Evidence approach for decision making. Example: Wensum Catchment: citizen science helps resolve pollution issue - CaSTCo(External link) | Monitoring using a statutory monitoring methodology and following an agreed moderation and quality control- diatom assemblage or macroalgal intertidal monitoring. Data could be used to contribute to Weight of Evidence approach for decision making. Example: | Flow monitoring using regulation standard kit (Environment Agency equivalent), with appropriate training, quality assurance and quality control in place and following Environment Agency direction on site location and sampling frequency. Example: |
3 | Data collected and analysed to professional standards and meets data and monitoring quality control standards gaps with a resilient and robust management system behind it enabling long term continuity of monitoring service. | Supplement statutory monitoring to complete spatial and temporal data and evidence gaps. | Direct bacterial load monitored using in situ monitoring equipment or samples collected and laboratory analysed by an accredited laboratory using appropriate thresholds. Examples: The Big Windermere Survey | Freshwater Biological Association(External link) | Real-time continuous monitoring with service level agreement for calibration and maintenance and a traceable quality assurance process. Example: Water quality sensors | Smarter Water Catchment(External link)
| Biodiversity citizen science monitoring data uploaded, and quality assured by the National Biodiversity Network is used by the Environment Agency when considering the impacts of planning applications and permits on wildlife. Example: | Rainfall monitoring- long term regular rainfall recording used by the Met Office. Example: |
Table 3: Examples of tiers within citizen science monitoring.
River type for Water Framework Directive (WFD) classification
Rivers vary naturally across England according to their hydrology, geology, biology, chemistry, and physical habitat. These five variables combine to create very different rivers in terms of their ecology, and it is essential to factor these variables in, when making informed decisions regarding WFD classification for biological, chemical and physical quality elements.
For example, a mountainous stream in Cumbria can expect a different invertebrate diversity and abundance to that of a lowland chalk stream in Hampshire. A stream in one catchment may have a geology which is different to a stream in neighbouring catchment and therefore we can expect the ecological community to be different.
When collecting data to understand a river’s health, it is important to place the data into the context of that river type to support a better understanding of that river’s health and the implications for its management.
Ensuring a river’s health is maintained for the effective conservation and/or restoration of the river and its ecology, classification thresholds are essential to help us understand the current and ongoing state of a river health.
Altitude | Annual mean Alkalinity (as CaCO3 mg/l) | Type | High
| Good
| Moderate
| Poor |
<80 | <50 | Type 1 | 0.03 | 0.05 | 0.15 | 0.5 |
>80 | <50 | Type 2 | 0.02 | 0.04 | 0.15 | 0.5 |
<80 | >50 | Type 3 | 0.05 | 0.12 | 0.25 | 1 |
>80 | >50 | Type 4 | 0.05 | 0.12 | 0.25 | 1 |
Table 4: WFD Standards for annual mean Soluble Reactive Phosphorus (mg/L)
Site altitude Alkalinity (Calcium Carbonate - CaCO3) mg/L | <10 mg/l
| 10-50 mg/l
| 50-100 mg/l
| 100-200 mg/l | >200 mg/l |
< 80 metres | Type 1 | Type 2 | Type 3 | Type 5 | Type 7 |
> 80 metres |
|
| Type 4 | Type 6 |
|
Table 5: Type categorisations as reference for table 4.
River Type | High
| Good
| Moderate
| Poor |
Upland and Low Alkalinity and High alkalinity salmonid river | 80 | 75 | 64 | 50 |
Lowland and High Alkalinity | 70 | 60 | 54 | 45 |
Table 6: WFD Standards for Dissolved Oxygen Saturation (%)
Ammoniacal nitrogen fact sheet
What is Ammoniacal Nitrogen?
Ammoniacal Nitrogen is the combined measure of two states of inorganic nitrogen ammonia (NH3) and ammonium (NH4+).
Natural Sources of Ammoniacal Nitrogen in Rivers include:
● Decomposition of organic matter
● Excretion from animals
Anthropogenic Sources of Ammoniacal Nitrogen include:
● Raw sewage
● Agricultural run-off (fertilisers and excretion from livestock)
● Industrial processes
Chemical Name | Also known as |
Ammoniacal Nitrogen (NH4-N) | Total Ammonia; Ammonia Nitrogen |
Ammonia (NH3) | Unionised ammonia, free ammonia, toxic ammonia |
Ammonium (NH4+) | Ionised ammonia, less toxic ammonia |
Table 7: Chemical and common names.
Water Framework Directive Thresholds for Ammoniacal Nitrogen in Rivers
River Type | High
| Good
| Moderate
| Poor |
Upland and Low Alkalinity | 0.2 | 0.3 | 0.75 | 1.1 |
Lowland and High Alkalinity | 0.3 | 0.6 | 1.1 | 2.5 |
Table 8: Water Framework Directive standards for Ammoniacal Nitrogen (mg/l)
For reference:
● Lowland < 80 metres
● Upland > 80 metres
● High Alkalinity > 50mg/L CaCO
● Low Alkalinity < 50mg/L CaCO
Understanding Water Quality Data and What it means for River Health
pH (Power of Hydrogen)
● pH describes how acid or alkaline a waterbody is: pH > 7 is alkaline; pH < 7 is acidic.
● Background pH is dependent on local geology.
● Extreme pH can cause ecological problems due to encouraging the formation of toxic ammonia (see ammoniacal nitrogen)
● Photosynthesis removes dissolved CO2 from the water and leads to an increased pH.
Temperature
● Water temperature generally changes with prevailing atmospheric temperature.
● Temperature has a fundamental influence on aquatic organisms, ecological processes and potency of pollutants.
● The ability of water to hold dissolved oxygen reduces as water temperature increases, therefore there is a daily and seasonal pattern observed with this parameter.
● Abrupt changes in the temperature can indicate inputs to a waterbody. For example, when it rains or when effluent is introduced to a river.
Conductivity
● Conductivity measures the total salts dissolved in water by its ability to conduct an electric current.
● Background levels vary depending on the local geology of the catchment.
● Baseline values can range from 100 – 2000 µS/cm.
● Upland streams generally have a lower conductivity, with lowland streams generally having a higher conductivity value as the river receives more minerals from a larger catchment area.
● Changes in conductivity can indicate inputs to a waterbody such as rainfall, industrial and sewage effluent, road run off and gritting run off during winter months.
● Rainfall has a diluting effect on conductivity, lowering the value in µS/ cm. However agricultural or road run off following a significant rainfall event will generally increase conductivity levels as run off starts to enter the waterbody.
Dissolved Oxygen Concentration
● Dissolved oxygen concentration is a measure of the amount of oxygen dissolved in the water, expressed in mg/L. Dissolved oxygen is essential for all aquatic life.
● Waterbodies receive oxygen via diffusion from the atmosphere and as a product of photosynthesis from aquatic plants.
● Mixing of the different layers of water within a river, generates turbulence and this increases diffusion of oxygen from the atmosphere to the river. Turbulence is characteristic of rivers in mountainous environments and in lowland streams following a rainfall event.
● Dissolved oxygen concentrations reduce as temperature increases, so dissolved oxygen concentrations are generally lower in summer.
● As pollutants enter a river, bacteria breakdown those pollutants using up greater amounts of dissolved oxygen in the process, reducing the availability of oxygen for aquatic organisms.
● Therefore, with warmer temperatures and less rainfall during the summer months, any pollution entering a river can have a larger impact on the ecology of rivers.
Dissolved Oxygen Saturation
● Dissolved oxygen saturation is a ratio which measures the amount of dissolved oxygen in the water against the maximum amount of oxygen that could be dissolved in the water, at that temperature and pressure.
● The result is expressed as a percentage.
● Waterbodies with a dissolved oxygen saturation > 70% is considered good; < 20% is considered bad.
Nitrate as N
● Nitrate (NO3-) is an essential nutrient for aquatic organisms however excessive amounts from agricultural run-off and sewage effluent can damage the ecology of rivers.
● Bacteria can process ammoniacal nitrogen to nitrate in rivers, when there is sufficient dissolved oxygen in the water.
● Excessive nitrate can cause algal blooms and reductions in dissolved oxygen concentrations.
Ammoniacal Nitrogen
● Ammoniacal Nitrogen is a combined measure of two states of nitrogen dissolved in water: Ammonia (NH3) and Ammonium (NH4+).
● The relative proportion of these two states (ammonia and ammonium) is affected by pH and temperature. An increase in pH or temperature increases the proportion of ammonia (NH3).
● In general, < 10% of total ammonia is in the toxic NH3 form when pH < 8.0. So, as the temperature and/or alkalinity of a water body increases, ammoniacal nitrogen becomes particularly toxic to fish and aquatic organisms.
● Ammonium has various sources including excretion from animals (livestock and sewage), decay of organic matter and agricultural fertiliser.
● It is a nutrient necessary for plant and algal growth but excessive amounts in a river can cause a waterbody to become eutrophic causing algal blooms. When algae eventually die, more dissolved oxygen is used by bacteria to breakdown the algae, so there is less dissolved oxygen available in the waterbody for aquatic organisms.
Orthophosphate, reactive as P
● Orthophosphate or dissolved phosphate is the bioavailable form of phosphorus.
● This nutrient, in small concentrations is essential for a healthy freshwater ecosystem as dissolved phosphate is essential for plant and algal growth.
● Excessive amounts derived from fertilisers and sewage discharges can cause eutrophication and reduced dissolved oxygen concentrations.
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