Regulatory Method (WAT-RM-37)
Contents
1. High profile cases such as Loch Leven illustrate the difficulties of reversing the process of eutrophication once damage has occurred The table below details the mechanism by which phosphorus is derived from these activities and the loading that each contributes 4 of 18 Uncontrolled if printed v2 Jul 2014 oo Purpose Scope and Background Table 1 Loadings and Mechanisms for Phosphorus Release from Various Activities Activity and primary Mechanism for P Loading control mechanism release Sewage discharges Phosphorus is present in This data is currently via CAR authorisation the effluent being updated Please see WAT RM 03 contact a PLUS user Regulation of Sewage for further information Discharges to Surface Waters Fish farming Fish feed and faeces from A loading of 10kg P per via CAR authorisation the fish tonne of Atlantic salmon smolt should be used unless the applicant can sufficiently justify the use of a different figure Note The figure can be substantially higher or lower for rainbow trout cages Forestry Application of phosphate Data on loading from via planning see fertilisers or nutrient different land uses is Guidance on the Water releases following large available in the PLUS Framework Directive scale felling operations model and is dependant including river basin especially via sediment on slope planning and CAR GBR run off Farming Surface run off following Data on2. see Guidance on the Water Framework Directive including river basin planning on SEPA s Planning website The principles can also be used for other river basin management planning purposes e g to help inform source apportionment studies It covers all discharges of phosphorus into lochs including direct discharges for example from cage fish farms large sewage treatment facilities small sewage discharges from a few houses and from diffuse sources such as forestry or agriculture 1 2 Background Nutrient enrichment with phosphorus is recognised as a major threat to water quality and the status of Scottish freshwater lochs Tourist developments fish farming and land use change have resulted in nutrient inputs to many standing water bodies Where nutrient inputs are significant they can give rise to eutrophication significantly increasing the growth of phytoplankton in the loch This can result in the growth of phytoplankton populations to nuisance proportions giving rise in extreme cases to algal blooms Between 45 and 90 of blooms of blue green algae are thought to produce toxins These toxins are largely retained within the blue green algal cells during their development and growth phases and are released in the main on cell death These algal blooms can damage the value of the resource for industry potable water supplies nature conservation fisheries and recreation and indicate a significant change in the loch ecology
3. by which it can be determined if the amount of available capacity taken up by the input is acceptable Step 6 Interpretation of Results There are a number of issues that need to born in mind when interpreting the results of the PLUS model and determining the amount of available capacity which can be allocated to a particular activity within the acceptable range specified by WAT RM 21 No Deterioration and Allocation of Capacity These issues are listed below 10 of 18 Uncontrolled if printed v2 Jul 2014 SER Assessing the Impact of an Activity Ecological status data from biological sensitive elements Although there is a strong relationship between elevated phosphorus concentrations and impacts on loch ecology it is difficult to predict with absolute certainty how any particular loch will respond to elevated phosphorus concentrations Other nutrients may limit the growth of phytoplankton in some lochs In others grazing by zooplankton may reduce the sensitivity of the loch to enrichment and reduce the incidence of algal blooms This all contributes to the uncertainty in scale of ecological change in response to elevated phosphorus concentrations When determining the amount of available capacity which can be allocated to a particular activity within the acceptable range specified by WA T RM 21 No Deterioration and Allocation of Capacity account should be taken of any ecological data from biologically sensitive elements suc
4. for calculating site specific standards Description Variable Data Comments Entry Mean depth m 10 0 Actual or modelled variables Altitude m 226 0 Altitude from base datum Reference alkalinity Enter either a value in mEQ I mEQ l or mg l Calculation will take mEQ result in preference to mg l 100 00 mg so leave blank unless you have data Calculated Reference alkalinity 2 000 Reference alkalinity used in variables mEQ I calculation Morpho edaphic index 0 200 MEI Log TP 0 980 Log1o total phosphorus To calculate site specific standards EQ staff should enter the appropriate values into the pink boxes using the current values provided by EQ The calculated boundaries are returned and can be checked against the existing boundaries held by EQ Principal Specialist Scientist The new data can then be input into the relevant boxes and the revised standards derived NOTE The Loch Policy Reference Conditions form preferentially takes data given in mEQ I If using mg l data ensure you leave the mEQ I box blank v2 Jul 2014 Uncontrolled if printed 15 of 18 SEPA Regulatory Method WAT RM 37 A 5 Application of revised standards If new data are used to revise the standards applied to a loch these should be incorporated into SEPA s classification system so any further classifications use the most current data This only applies to baseline lochs i e water bodies reported to
5. impacts should be determined using best judgement and expert advice from ecology Impacts on Other Water Users and Nature Conservation Sites Discharges should be treated to a standard to ensure that there are no adverse impacts e g de oxygenation on other water users e g bathing beaches or designated nature conservation sites If the activity results in an unacceptable impact then application of the measures detailed in the table if not already undertaken may reduce the input of phosphorus from the activity to a level which is acceptable The model can then be re run to determine if the impacts are acceptable Table 2 Mitigation Measures Activity Mitigation Measure Sewage discharges Phosphorus removal at WWTW Contact the Q amp S team web pages in relation to plans for phosphorus removal in current Scottish Water sewage discharges The outfall from any discharge should be designed to minimise the impacts on the environment and should be located below the lowest water level in the loch at the point of discharge to ensure mixing and dispersal of the effluent WAT RM 03 provides further information on the process of regulating sewage discharges Fish farming Use of low phosphorus feed and or collection and treatment of waste arising from the farm Forestry Follow The Water Environment Controlled Activities Scotland Regulations 2005 General Binding Rules and the Forestry Commission Forests and Water Guidelines Thi
6. issued with cover note about PLUS model availability v1 2 Figure 1 first box revised to read Derive site specific standard v2 Revised to reflect the Standards Directions 2014 Notes References Linked references to other documents have been disabled in this web version of the document See the References section for details of all referenced documents Printing the Document This document is uncontrolled if printed and is only intended to be viewed online If you do need to print the document the best results are achieved using Booklet printing or else double sided Duplex 2 on 1 A4 printing both four pages per A4 sheet Always refer to the online document for accurate and up to date information 2 of 18 Uncontrolled if printed v2 Jul 2014 Table of Contents 1 Purpose Scope and Background sesssseeeeeeeeeeeeeeeeeeeeeeeneennn ennen nenne nennen 4 1 1 P rpose and CO ae a a a 4 1 2 72 8 lt 6 0 0 0 sisses E E EEE 4 2 Classification and Environmental Standards cccceeeeeeeeeeeeeeeeeeeeeeeeeeeees 6 2 1 Environmental STAN ANOS gcse ce tiie cen teense aceietenmcenanenec nie dennsnneceanthiedenasenae 6 22 Classification ecne E atte ieee oece ela eaeanie 6 3 Assessing the Impact of an Activity 0 0 0 0 cceeeeeeceecceeeeeeeeeeeeeeeaeeeeeeeeeeeeeseenaeees 6 3 1 Allocation of capacity secteceststceetca eases cece ess cece cue c econ 6 32 WINS PIU SP WOU loge cceccvceteecceex eer
7. the EU non baseline lochs have standards applied in regulation but do not have classification standards WAT FORM 30 Derivation of Loch Total Phosphorus Site specific Standards must be completed by EQ and forwarded to the Monitoring and Classification Officer Principal Specialist Scientist The Standing Waters Task Group will periodically review any amended site specific standards to ensure the correct methodology is followed A 6 Site specific standards spreadsheet Use the Loch Policy Reference Conditions form QP ES EQ P 002 to calculate site specific standards 16 of 18 Uncontrolled if printed v2 Jul 2014 References NOTE Linked references to other documents have been disabled in this web version of the document See the Water gt Guidance pages of the SEPA website for Guidance and other documentation www sepa org uk water water_regulation guidance aspx All references to external documents are listed on this page along with an indicative URL to help locate the document The full path is not provided as SEPA can not guarantee its future location Key References m WAT RM 03 Regulation of Sewage Discharges to Surface Waters m WAT RM 21 No Deterioration and Allocation of Capacity E WAT SG 53 Environmental Standards for Surface Waters WAT FORM 30 Derivation of Loch Total Phosphorus Site specific Standards Q Pulse Documents Use the doc number as a search string in Q Pulse to find the document d
8. Operations send to Environmental Quality staff or another PLUS user E information on the location and type of discharge land use change data on loading e g for fish farms or other direct discharges or land use modification e g new forestry plantation amap in digital form if possible for land use change e g forestry so this can be input into the model m Paleoecological assessment results if available these may be particularly relevant for freshwater cage fish farm proposals This information should be requested from the applicant and highlighted during pre application discussions v2 Jul 2014 Uncontrolled if printed 9 of 18 SE PAP Regulatory Method WAT RM 37 Step 3 Check of Model Output of Current Conditions EQ or PLUS user runs the PLUS model with the current data i e before the new discharge or land use change EQ checks that the current modelled concentration and the actual measured concentration or grouped concentration that was used for classification are similar Where there is a significant difference in the modelled and measured concentrations then the confidence in the classification data and the modelled result must be examined in order to determine which should be used Discrepancies between modelled and measured concentrations may arise where for example the current classification is based on monitoring data from another loch in a group or where landuse in this area changed signifi
9. Total Phosphorus Site specific Standards The GIS Intranet Site should be used to obtain water body ID where appropriate and GB lakes ID Forms without an identifier cannot be processed A 3 Classification approach The standards used to classify lochs for total phosphorus were proposed by the UK Technical Advisory Group and incorporated into the Standards Directions issued to SEPA 14 of 18 Uncontrolled if printed v2 Jul 2014 a Derivation of loch total phosphorus site specific standards In brief each loch has a defined reference total phosphorus value which is used to derive standards for each boundary High Good Good Moderate Moderate Poor and Poor Bad The measured total phosphorus value is then compared against the standards to determine the class The existing standards and the data used to derive them can be found by contacting EQ Principal Specialist Scientist EQ will be able to detail the existing standards used and the altitude alkalinity and mean depth results used to calculate the reference total phosphorus value These results may be either modelled or derived from measured data In either case changes to the modelled data or measured parameters may result in a change to the standard applied A 4 Calculation of site specific standards Use Loch Policy Reference Conditions QP ES EQ P 002 to calculate site specific standards by EQ An example of this form is provided below Table 3 Entry variables
10. a4 eee SE PAD Scottish Environment Protection Agency Water Use Regulatory Method WAT RM 37 Regulation of Phosphorus Discharges to Freshwater Lochs Version v2 Released Jul 2014 Copyright and Legal Information Copyright 2014 Scottish Environment Protection Agency SEPA All rights reserved No part of this document may be reproduced in any form or by any means electronic or mechanical including but not limited to photocopying recording or using any information storage and retrieval systems without the express permission in writing of SEPA Disclaimer Whilst every effort has been made to ensure the accuracy of this document SEPA cannot accept and hereby expressly excludes all or any liability and gives no warranty covenant or undertaking whether express or implied in respect of the fitness for purpose of or any error omission or discrepancy in this document and reliance on contents hereof is entirely at the user s own risk Registered Trademarks All registered trademarks used in this document are used for reference purpose only Other brand and product names maybe registered trademarks or trademarks of their respective holders Update Summary Version Description v1 0 First issue for Water Use reference using approved content from the following documents RM 37 Regulation of discharges to freshwater lochs dec2010 doc NOTE WAT RM 37 replaces WAT SG 10 v1 1 Re
11. ata with the appropriate total phosphorus 6 of 18 Uncontrolled if printed v2 Jul 2014 SEPA Scottish Environment Protection Agency Classification and Environmental Standards standard Some loch water bodies have been grouped so that the monitoring data from one loch can be applied to the others for classification purposes Information on classification is available on the GIS Intranet Site To view this information add and make active the WFD classification theme and then make the loch classification theme visible The current classification can be seen by clicking on to identify the relevant loch A detailed break down of the classification for each parameter can be seen by clicking on the water body ID The flow chart below explains how classification is carried out Figure 1 Classifying Lochs for Phosphorus s appropriate Derive type altitude depth No 4 specific l and alkalinity standard ___ information available Ved Derive site specific _ standard _ v2 Jul 2014 Uncontrolled if printed 7 of 18 3 Assessing the Impact of an Activity 3 1 Allocation of capacity The allocation of capacity should be assessed for the loch water body as a whole SEPA s guidance on Allocation of Capacity and Protection of the Water Environment WAT RM 21 No Deterioration and Allocation of Capacity provides details on the capacity that can be allocated to a discharge into a loch This applies to all lo
12. cantly since the data set used in the model was produced Generally there is a presumption that if monitoring data for a loch is available that this should be used and the model input parameters should be adjusted so that the modelled results more closely match monitoring results However we would have low confidence if only one set of monitoring results per year were available Two samples a year are regarded as a minimum to provide confidence in the monitoring data so that this could be used in preference to the model output Which ever concentration is used to describe the current conditions the scale of change in the phosphorus concentration that the model predicts should be used as the definitive prediction of any increase Note the current total phosphorus concentrations in un monitored lochs can be predicted by the PLUS model Step 4 Predictive Modelling EQ runs the PLUS model with the new discharge landuse change to predict the change in phosphorus concentration which is likely to occur following the development e g forestry new sewage discharges or fish farming and whether this will result in any deterioration in status exceedance of allowable available capacity Step 5 Compare the Results with the Environmental Standard The results of the PLUS model should be compared to the environmental standard to determine if the standard will be exceeded WAT RM 21 No Deterioration and Allocation of Capacity sets out the principles
13. chs including peaty lochs 3 2 The PLUS Model The impact that a discharge e g sewage discharge or a landuse change will have on the concentration of phosphorus in all types of lochs can be predicted by the use of the PLUS model Therefore impacts on the loch can be predicted without the need for monitoring data The model contains and uses information on landuse slope and sewage discharges over the whole catchment to predict current and future phosphorus concentrations in the loch and compares this modelled concentration to the classification or regulatory standard for that loch It allows the user to change the landuse type areas or amount of phosphorus available for each type of landuse It also allows the user to change the numbers of sewage discharges and to add other point source discharges The model shows the amount of phosphorus input from various different sources which can help determine where action is required to effect an improvement in water quality It also allows consideration of the impacts on lochs downstream and shows the phosphorus loading into the loch which is coming directly from the catchment and that from upstream catchments The model also accounts for retention of phosphorus in the loch Figure 2 provides a summary of the PLUS model Further information on the PLUS model can be obtained from Environmental Quality or the PLUS user manual 1 Under the 1997 policy the allowable increase in concentration
14. e enere eaor ienee iorra Eere Fiar ret TEREE 6 3 3 Impact ASSESSMEM bins ccnccccrccssstsatcenccecccoesdasisancteacsenodsadssastansdoaaderdsanadoaadnecee 6 3 4 Determining the Application sisinssaasaisinanseineyixandernicceaianenesinceanrnteepdcendesnitanats 6 Annex A Derivation of loch total phosphorus site specific standards 6 A1 WAC WO I acces eee eee ee 6 A 2 SOV STI AINGS areca geere ere aerie rE cen eden EErEE ais Mas Ee E rele eE EEEa 6 A 3 Classification approach woscssisesdacscasscncdcnssnncdandsnnedanddnnodsnddnnodanddenodanidenodendienese 6 A 4 Calculation of site specific Standards ccccccccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeess 6 A 5 Application of revised Standards cccccccccccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeess 6 A 6 Site specific standards spreadsheet cccccceceeceeeeeeeeeeeeeeeeeeeeeeeeeeeeeess 6 Reference S aiseee A E 6 v2 Jul 2014 Uncontrolled if printed 3 of 18 1 Purpose Scope and Background 1 1 Purpose and Scope This guidance describes the process of how discharges of phosphorus into all types of freshwater loch should be considered It can be used to assess Applications for licences considered under The Water Environment Controlled Activities Scotland Regulations 2005 e g fish farms and sewage discharges Indicative Forestry Strategies Forest Design Plans and large scale Forestry planting and felling consultations For further details please
15. h as data relating to phytoplankton or macrophytes to confirm whether there is or whether there is likely to be a problem Specifically the classification status class proximity to boundary uncertainty of relevant ecological elements must be taken into account alongside the predicted impact on total phosphorus status Where the loch is at less than good status or at risk of deterioration as defined by WAT RM 21 No Deterioration and Allocation of Capacity for parameters which are linked to phosphorus eg phytoplankton diatoms and macrophytes an ecologist should be consulted for advice However it is important regardless of the information on ecological status that the activity does not result in a breach of phosphorus standard In cases where there is uncertainty over the phosphorus status of a loch a paleoecological study may provide useful extra information This can be particularly useful for un monitored lochs for other cases where there is uncertainty over the phosphorus status of a loch or for ascertaining the impact on phosphorus from existing developments Paleoecology information may be particularly relevant to significant developments from which waste will be discharged to the water environment in an untreated form such as freshwater cage fish farming A paleoecological study will provide additional information on current and reference phosphorus conditions that can be assessed in relation to standards This is particularly u
16. irectly Loch Policy Reference Conditions QP ES EQ P 002 Other References m Forests and Water Guidelines The Forestry Commission http www forestry gov uk m GIS Intranet Site on SEPA Intranet http stir app gis04 gis Guidance on the Water Framework Directive including river basin planning LUPS_GU7 http www sepa org uk planning aspx m PEPFAA Code of Good Practice Prevention of Environmental Pollution From Agricultural Activity Scottish Executive www scotland gov uk E Standards Directions 2014 e The Scotland River Basin District Surface Water Typology Environmental Standards Condition Limits and Groundwater Threshold Values Directions 2014 e The Solway Tweed River Basin District Surface Water Typology Environmental Standards Condition Limits and Groundwater Threshold Values Scotland Directions 2014 NOTE This link provides access to the documents via a managed SEPA intranet page The full set of Standards Directions for each river basin district in Scotland can also be found via the Publications page of the Scottish Government website www scotland gov uk Publications m UKTAG Water Framework Directive www wfduk org v2 Jul 2014 Uncontrolled if printed 17 of 18 a4 A A Scottish Environment tectio Regulatory Method WAT RM 37 Protection Agency End of Document 18 of 18 Uncontrolled if printed v2 Jul 2014
17. loading from via CAR GBR the application of different land uses is manures and slurries or available in the PLUS sediment run off from model and is dependant farmland on slope v2 Jul 2014 Uncontrolled if printed 5 of 18 2 Classification and Environmental Standards 2 1 Environmental Standards The Standards Directions 2014 are set out in The Scotland River Basin District Surface Water Typology Environmental Standards Condition Limits and Groundwater Threshold Values Directions 2014 m The Solway Tweed River Basin District Surface Water Typology Environmental Standards Condition Limits and Groundwater Threshold Values Scotland Directions 2014 These Directions require SEPA to apply an environmental standard to lochs when exercising its functions under the Water Environment Controlled Activities Scotland Regulations 2011 It also specifies that these standards should be used to classify water bodies in line with the Water Environment and Water Services Scotland Act 2003 The standards set out in the 2009 direction are based on work carried out by the UKTAG Water Framework Directive Lochs in a natural condition contain and receive different amounts of phosphorus from their catchments The natural state of their fertility varies and the impact of additional phosphorus depends on the sensitivity of the loch Physicochemical factors affecting the sensitivity of a loch to phosphorus inputs include the alkalinity of
18. s should always be adhered to Farming Follow The Water Environment Controlled Activities Scotland Regulations 2005 General Binding Rules and the Scottish Government PEPFAA Code of Good Practice This should always be adhered to 3 4 Determining the Application The steps in section 3 3 should be followed to determine if the environmental impacts as a result of the activity are likely to be acceptable Licence conditions should then be set using the information above If following the assessment it appears that the input is likely to result in an unacceptable environmental impact then 12 of 18 Uncontrolled if printed v2 Jul 2014 SEPAN Assessing the Impact of an Activity m Fora CAR licence the licence should be refused or licence conditions added which would result in the environmental impact of an activity being acceptable E Fora planning response SEPA should object to the application or make clear to the planning authority the conditions that would be necessary to make the environmental impact of the activity acceptable v2 Jul 2014 Uncontrolled if printed 13 of 18 Annex A Derivation of loch total phosphorus site specific standards A 1 Introduction Lochs can be classified using a standard specific to the loch water body site specific or where suitable data aren t available standards specific to the type of loch Type specific standards provide less precise classification boundaries
19. seful in the context of existing freshwater cage fish farms that are seeking an increase in their production The possibility of the applicant commissioning a paleoecological study by a competent person should ideally be part of pre application discussion Advice on undertaking such a study is available from Science Mixing The PLUS assumes full mixing within the loch This is considered to be valid for most lochs since phosphorus is a conservative substance which is not readily broken down by chemical or physical processes Phosphates may be assimilated by algae or macrophytes but will subsequently be released to the waterbody and recycled Therefore over time phosphates have the potential to exert an influence on the status of the loch well beyond the immediate point of release and will influence trophic conditions over a waterbody as a whole However it is possible that full mixing may not take v2 Jul 2014 Uncontrolled if printed 11 of 18 SE PAP Regulatory Method WAT RM 37 place in very large lochs with highly separated sub basins if the inflow is very near the outflow allowing possible short circuiting or if there are currently localised impacts In these scenarios the model outputs should be treated with caution as it is likely that the calculation of the residence time is inaccurate It should be noted that it is unlikely that the data or tools to carry out more detailed modelling will be available and in these cases the
20. the water and the depth an indicator of the extent to which a lake is able to retain its phosphorus naturally As a result each loch ideally requires its own standard The Directions allow loch water bodies to be classified using a site specific standard for each loch water body Where suitable data for a specific loch are not available the Directions set out type specific standards for each type of loch water body These are typical standards for phosphorus depending on a variety of loch characteristics such as those set out above These are not currently available on the GIS intranet site but can be obtained from SEPA s Environmental Quality EQ team for all Scottish lochs of gt 1ha in surface area Further information on the classification and standards for lochs can be found in WAT SG 53 Environmental Standards for Surface Waters Type specific standards provide imprecise classification boundaries with consequential implications for regulation Where suitable data are available more appropriate site specific standards should be derived to aid the process of regulation and the determination of appropriate and defensible standards for inclusion in CAR licences Further information on the derivation of site specific standards can be found in Annex A 2 2 Classification Total phosphorus is one of a number of quality elements on which lochs are classified under the WFD SEPA has classified loch water bodies by comparing actual monitoring d
21. was considered to be flexible with provision for excedence of the then 20 increase rule in highly coloured peaty lochs The UK Technical Advisory Group considered that under the new classification scheme that there is currently insufficient information to justify different phosphorus standards for humic lochs Because of this no different approach to the allocation of available capacity for peaty lochs is advocated Based on the OECD equation 8 of 18 Uncontrolled if printed v2 Jul 2014 ne NN S E PAW Scottish Environment Protection Agency Assessing the Impact of an Activity Figure 2 Summary of the PLUS model Landuse Predict TP Account for ET concentration retention in A loch Other Discharges J Inputs from uP stream Classification standard Change landuse add isch to loch 3 3 Impact Assessment The steps involved in assessing the impact of a discharge containing phosphorus into a loch are detailed below Step 1 Derive site specific standard not usually necessary Where new data on depth or alkalinity is available either provided by the applicant or obtained by SEPA Local Operations should follow the procedure in Annex A to request that a site specific loch standard is calculated by EQ Where there is uncertainty whether a new standard needs to be calculated Local Operations should contact EQ Step 2 Local Operations Sends Data to EQ Local
22. with consequential implications for regulation This annex sets out a mechanism to derive a loch total phosphorus site specific standard This can be carried out where further information on depth or alkalinity becomes available This is mainly carried out by EQ on request of Local Operations or science A 2 Governance If Local Operations become aware of any new data on depth or alkalinity of a loch then the Local Operations officer should contact EQ to determine if a new standard can be calculated e g EQ will determine if the data is suitable and different to that previously used to calculate a site specific standard or where the loch classification is currently based on a type specific standard The Environmental Quality Unit EQ will lead on the calculation and necessary revisions of the site specific standards They will do so when a request is received from Local Operations or science colleagues requests will normally be dealt with within 14 days Calculation of a site specific standard is only appropriate when improved data are available for both of the following attributes Alkalinity minimum of 4 samples in a calendar year m Mean depth measured Altitude is assumed to be constant although revised figures can be submitted It is the responsibility of the function requesting the calculation of a site specific standard to arrange for the provision of improved data and submit it to EQ on WAT FORM 30 Derivation of Loch
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