--- title: "Septic Tank and PTP upgrade: opportunity mapping & modelling" ocid: "ocds-h6vhtk-050bea" canonical_url: "https://d3tenders.com/contract/?ocid=ocds-h6vhtk-050bea" markdown_url: "https://d3tenders.com/contract/ocds-h6vhtk-050bea.md" json_url: "https://d3tenders.com/contract/ocds-h6vhtk-050bea.json" source: "Find A Tender Service" current_stage: "Award" buyer: "NATURAL ENGLAND" published: "2025-06-20" --- # Septic Tank and PTP upgrade: opportunity mapping & modelling Buyer: NATURAL ENGLAND Current stage: Award OCID: ocds-h6vhtk-050bea [View canonical contract page](https://d3tenders.com/contract/?ocid=ocds-h6vhtk-050bea) [Download OCDS JSON](https://d3tenders.com/contract/ocds-h6vhtk-050bea.json) ## Summary Natural England, a central government public authority based in London, has recently completed an open procurement process for the project titled "Septic Tank and PTP Upgrade: Opportunity Mapping & Modelling." The procurement sought to identify opportunities for upgrading ineffective septic tanks and package treatment plants (PTPs) with more efficient alternatives to enhance water quality across 27 designated catchments in the UK. The procurement process, which involved open competition below the threshold, was awarded to Viridian Logic Ltd, a small to medium enterprise (SME), with the contract active from 16th June 2025 to 20th October 2025. The award stage was reached after submissions were received by 3rd June 2025, and the contract was signed on 12th June 2025. The total gross contract value is £50,400. This tender offers significant opportunities for businesses specialising in environmental services and geographic information (GI) technology. There is potential for firms skilled in nutrient reduction modelling, cost estimation for PTP upgrades, and method development using national datasets. The contract requires managing technical deliverables such as creating reproducible methodologies, datasets, codes, and technical reports, providing an excellent opportunity for businesses to showcase expertise in sustainable environmental management practices. SMEs, particularly those supporting complex environmental and data analysis projects, are well-suited to engage in similar opportunities to innovate and grow through public contracts. ## Notice Natural England are exploring the use of replacing inefficient septic tanks and package treatment plants (PTPs) with PTPs that have a higher treatment efficiency for phosphorus and nitrogen to improve water quality in up to 27 catchments. The anticipated catchments are detailed in a table in the Annex. For each catchment, we require estimates of the following: Scale of opportunity: The scale of opportunity (in units) of upgrading inefficient septic tanks and PTPs in each catchment. This will need to be mapped using GI software. Nutrient reduction: The potential nutrient reduction achieved (in kg/TP and kg/TN) for phosphorus and/or nitrogen depending on the NN catchment from replacing inefficient septic tanks and PTPs with more efficient PTPs. Cost: The cost of delivering replacement PTPs and septic tanks at-scale. In addition to the estimates above, the following deliverables are required: Methodologies: Will need to be developed based on Natural England's existing methods and in consultation with Natural England and created using national datasets. Datasets & code: Natural England will need the ability to run the model independently once the commission is complete. Any datasets and code used to create the methodology, estimates and mapping will need to be made available to NE upon completion. Technical reports: The decided upon methodology will need to be written into a report to ensure it is reproducible by others. This should highlight any uncertainties where they arise. These deliverables will need to be managed and administered by Natural England once the project is complete and are likely to be amended and updated over time. ## Key Details | Field | Value | | --- | --- | | Publication source | Find A Tender Service | | Latest notice | https://www.find-tender.service.gov.uk/Notice/033922-2025 | | Notice type | UK7 - Contract Details Notice | | Procurement type | Standard | | Procurement category | Services | | Procurement method | Open | | Procurement method details | Below threshold - open competition | | Tender suitability | SME | | Awardee scale | SME | | All stages | Tender, Award | ## Dates | Field | Value | | --- | --- | | Publication date | 20 Jun 2025 | | Submission deadline | 3 Jun 2025 | | Future notice date | Not specified | | Award date | 11 Jun 2025 | | Contract period | 15 Jun 2025 - 20 Oct 2025 | | Recurrence | Not specified | ## Values | Field | Value | | --- | --- | | Tender value | £48,000 | | Lots value | £48,000 | | Awards value | Not specified | | Contracts value | £42,000 | ## Status | Field | Value | | --- | --- | | Tender status | Complete | | Lots status | Complete | | Awards status | Active | | Contracts status | Active | ## Buyer | Field | Value | | --- | --- | | Main buyer | NATURAL ENGLAND | | Locality | LONDON | | Post town | South West London | | Postcode | SW1P 4DF | | Country | England | | ITL 1 | TLI London | | ITL 2 | TLI3 Inner London - West | | ITL 3 | TLI35 Westminster and City of London | | Local authority | Westminster | | Electoral ward | St James's | | Westminster constituency | Cities of London and Westminster | | Delivery location | Not specified | ## Supplier | Field | Value | | --- | --- | | Number of suppliers | 1 | | Supplier names | VIRIDIAN LOGIC | ## CPV Codes ### Divisions - 90 - Sewage, refuse, cleaning and environmental services ### Codes - 90700000 - Environmental services ## Release History - 20 Jun 2025 at 08:29 - Award - UK7 - Contract Details Notice - https://www.find-tender.service.gov.uk/Notice/033922-2025 - 2 Jun 2025 at 14:17 - TenderUpdate - UK4 - Tender Notice - https://www.find-tender.service.gov.uk/Notice/029212-2025 - 30 May 2025 at 13:07 - TenderUpdate - UK4 - Tender Notice - https://www.find-tender.service.gov.uk/Notice/028819-2025 - 30 May 2025 at 07:18 - TenderUpdate - UK4 - Tender Notice - https://www.find-tender.service.gov.uk/Notice/028631-2025 - 23 May 2025 at 14:39 - TenderUpdate - UK4 - Tender Notice - https://www.find-tender.service.gov.uk/Notice/026781-2025 - 22 May 2025 at 10:47 - TenderUpdate - UK4 - Tender Notice - https://www.find-tender.service.gov.uk/Notice/024647-2025 - 22 May 2025 at 10:43 - TenderUpdate - UK4 - Tender Notice - https://www.find-tender.service.gov.uk/Notice/024641-2025 - 21 May 2025 at 13:44 - TenderUpdate - UK4 - Tender Notice - https://www.find-tender.service.gov.uk/Notice/024028-2025 - 14 May 2025 at 12:26 - TenderUpdate - UK4 - Tender Notice - https://www.find-tender.service.gov.uk/Notice/021258-2025 - 2 May 2025 at 07:41 - Tender - UK4 - Tender Notice - https://www.find-tender.service.gov.uk/Notice/018628-2025 ## Documents - https://www.find-tender.service.gov.uk/Notice/033922-2025 20th June 2025 - Contract details notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/029212-2025 2nd June 2025 - Tender notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/028819-2025 30th May 2025 - Tender notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/028631-2025 30th May 2025 - Tender notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/026781-2025 23rd May 2025 - Tender notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/024647-2025 22nd May 2025 - Tender notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/024641-2025 22nd May 2025 - Tender notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/024028-2025 21st May 2025 - Tender notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/021258-2025 14th May 2025 - Tender notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/018628-2025 2nd May 2025 - Tender notice on Find a Tender - https://www.find-tender.service.gov.uk/Notice/Attachment/A-1065 RFQ - https://www.find-tender.service.gov.uk/Notice/Attachment/A-1066 Order Form - https://www.find-tender.service.gov.uk/Notice/Attachment/A-1067 Commercial Response - https://www.find-tender.service.gov.uk/Notice/Attachment/A-1387 Clarifications to Bidders' Questions - https://www.find-tender.service.gov.uk/Notice/Attachment/A-1571 Clarifications to Bidders Questions - https://www.find-tender.service.gov.uk/Notice/Attachment/A-1615 Clarifications to Bidders Questions - https://www.find-tender.service.gov.uk/Notice/Attachment/A-1778 Clarification to Bidders' Questions - https://www.find-tender.service.gov.uk/Notice/Attachment/A-1789 Clarification to Bidders' Questions - https://www.find-tender.service.gov.uk/Notice/Attachment/A-1820 Clarifications to Bidders Questions ## Notice URLs - https://www.legislation.gov.uk/ukpga/2023/54/contents ## Provenance This Markdown file is an alternate public rendering of the D3 Tenders contract record. The canonical page is https://d3tenders.com/contract/?ocid=ocds-h6vhtk-050bea. The underlying structured data is available as OCDS JSON at https://d3tenders.com/contract/ocds-h6vhtk-050bea.json.