Regulatory Method (WAT-RM-04)

1 Water UseRegulatory Method (WAT-RM-04)Indirect Sewage Discharges to GroundwaterVersion: : Oct 20192 of 33 Uncontrolled if Oct 2019 Copyright and Legal InformationCopyright 2019 Scottish Environment Protection Agency (SEPA).All rights reserved. No part of this document may be reproduced in any form or by anymeans, electronic or mechanical, (including but not limited to) photocopying, recording orusing any information storage and retrieval systems, without the express permission inwriting of :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 nowarranty, covenant or undertaking (whether express or implied) in respect of the fitness forpurpose of, or any error, omission or discrepancy in, this document and reliance on contentshereof is entirely at the user s own Trademarks.

2 All registered trademarks used in this document are used forreference purpose brand and product names maybe registered trademarks or trademarks of theirrespective issue for Water Use reference using approved content from the following now includes info on how to size soakaways; s7 added (Regulating willowtreatment systems); BR478: (Mound Filter Systems) added as reference doc and WAT-RM-22 links now refer to WAT-RM-34. / Various minor & text details revised; New base template applied, links to docs revised for newSEPA website, Nov new procedure for regulating willow treatment systems, Figs 1 & 2 minor modifications.(Jan 2011)v5 Expired CMS links reviewed and to mean effluent standards - new and changes to and of wording that SEPA are minded not to authorise discharges whereconnection to public sewer is non-domestic pe now specifies 'standard residential flow', intranet link : compost toilets/grey water; non-domestic septic tank updated to define existing and clarify paper application : Linked references to other documents have been disabled in this web versionof the document.

3 See the References section for details of all referenced the Document: This document is uncontrolled if printed and is only intended to beviewed you do need to print the document, the best results are achieved using Booklet printing orelse 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 Oct 2019 Uncontrolled if printed3 of 33 Table of Contents1. Key Process Pre-Application Unauthorised Authorised to the Public Sewer and Adoption by Scottish Discharges - Treatment Plant Certification to EN12566 Part the Registration Appropriate Licences (<50 ).

4 Unlicensed Areas on Licence Discharges from Properties Serving >50 Requirements when Dealing with a Discharge >50 the Regulating Willow Treatment Method (WAT-RM-04)4 of 33 Uncontrolled if Oct of and Risk Oct 2019 Uncontrolled if printed5 of 331. Key PointsThis guidance concerns indirect sewage discharges to groundwater . Forsewage discharges to surface waters please refer toWAT-RM-03: Regulation ofSewage Discharges to Surface Watersfor guidance is designed for use with the following licence templates: WAT-TEMP-04: Septic Tank Licence Template WAT-TEMP-05: Sewage Treatment Works (15-100pe) Licence Template6 of 33 Uncontrolled if Oct 20192.

5 Process FlowFigure 1 Decision Diagram for Sewage Discharges Indirect Oct 2019 Uncontrolled if printed7 of 333. Pre-Application ConsultationsA discharge to land is SEPA s preferred Method for the disposal of treatedsewage effluent where the ground conditions allow adequate infiltration of theeffluent and sufficient attenuation of the polluting nature of the toOther Considerationsfor guidance on: Multi-ownership discharges Separating surface water from treatment plantsAll references to the Technical Handbook refer to theTechnical Handbook:(Section 3: Environment). Existing Unauthorised DischargesWhen an existing unauthorised sewage discharge from a populationequivalent ( ) (see section ) of less than or equal to 50 is brought to theattention of SEPA, the discharge should be registered.

6 The threshold of (9 homes) is used for existing discharges, whereas 15 should beused for new sewage discharges. Existing means that the treatment systemhas been in use for more than two years before the date of : A proposed increase in for an existing unauthorised dischargeshould be assessed as a new discharge since there is an increase inenvironmental risk. However a pragmatic approach should be taken,depending on the scale of the increase and the resultant risk to application should be made, either online or by paper. If a paperapplication is made, SEPA Registry will register the discharge. It should benoted that for these existing discharges there will be no consultation withOPS and no assessment as to whether the discharge is causing anenvironmental impact.

7 Furthermore there will be no assessment as towhether the discharge may affect a Protected Area such as an areadesignated for nature In the situation where there are say 3 small septic tanks discharging to asingle soakaway, a registration should be issued for each septic tank. Thisallows for easier enforcement of registration unauthorised sewage discharge from a of more than 50 must belicensed. A date for submission of a full application should be agreed with thedischarger. Provided there is no evidence of an environmental impact (asdetermined by a site visit), the discharge should be licensed on the basis ofthe existing system. If there is an unacceptable impact, progressiveimprovements within a reasonable timescale, taking account of costs andbenefits, should be agreed with the discharger and conditioned within Method (WAT-RM-04)8 of 33 Uncontrolled if Oct Modifying Authorised Modifying Registered DischargesIf the of an existing registered discharge is increased ( due to ahouse extension or an additional house joining the system) the registrationrequires modification.

8 If the increases above 15 then a new applicationfor a simple licence should be procedure for variation of registrations as described inWAT-RM-09:Modifications to CAR Authorisationsshould be : Deemed registrations (previouslyNon-subsistence CoPA Consents)should be assessed in accordance with Modifying Licensed DischargesFor licensed discharges, changes to the licence such as an increase inloading requires a variation of the licence. Refer toWAT-RM-09: Modificationsto CAR Authorisationsfor Connection to the Public Sewer and Adoption byScottish WaterThe proliferation of small STWs and septic tanks in or near sewered areas isto be discouraged.

9 Disposal of foul drainage to the public sewer shouldalways be sought where practicable. This reinforces the need to take fulladvantage of the planning consultation process to ensure that, whereappropriate, connection to the public sewer is a planning requirement for newdevelopments. If connection to the public foul sewer is not a planningrequirement, SEPA must ensure that the discharge is appropriately regulatedto provide an adequate level of environmental protection. SEPA may refuse aCAR authorisation if a public foul sewer is in close proximity and theapplicant should be made aware of will normally refuse an application for authorisation to dischargesewage to surface waters or land where the site or proposed discharge pointis within, or immediately adjacent to, a Scottish Water sewered area.

10 SEPA seeks to refuse these applications on the basis of this type of treatment beinga less efficient and less sustainable use of the water will be considered where it is shown that connection to thesewer network is not reasonably should be made to Position StatementWAT-PS-06-08: Policy andSupporting Guidance on Provision of Waste Water Drainage in Settlementswhichsets out SEPA's policy principles on the provision of waste water drainagewithin and outwith settlements served by a strategic sewerage Oct 2019 Uncontrolled if printed9 of Population EquivalentPopulation equivalent ( ) for domestic housing is equivalent to the figure PinFlows and Loads(British Water Code of Practice)