Chemical and biological odour filters

Summary

Waterschap Vallei en Veluwe is seeking suppliers under two lots to provide filter media and inspect, maintain and repair chemical and biological odour-treatment installations at wastewater treatment plants and sewage pumping stations. The work also includes supplying and installing complete new installations when required. Each inspection must result in a report describing the installation and filter-media condition, any defects, and recommendations for repair or maintenance. Chemical filters are inspected twice a year; biological filters receive preventive maintenance four times a year. For the chemical-filter lot, the media must be dry, porous and pellet-shaped, based on aluminium oxide and/or activated carbon, with a particle diameter of 2–5 mm. It must have an H2S capture capacity of at least 45% per 100 kg of filter media and reduce H2S concentration by at least 95%; capacity must be substantiated by product specifications or test reports. For both lots, used media must be collected and disposed of in accordance with applicable requirements, adequate stock must be maintained, and the media must remove H2S and mercaptans/thiols and remain suitable when exposed to moisture. The contractor must be able to repair filters, install complete new units and provide advice when requested. Bids may cover one or both lots, but must cover the entire scope of each lot bid for. The initial framework agreement term is 2 years for chemical filters from 1 January 2027 and 1 year for biological filters from 1 January 2028; each agreement may be extended twice by 2 years. The estimated value and ceiling, excluding VAT, are EUR 450,000 and EUR 675,000 for the chemical lot, and EUR 640,000 and EUR 960,000 for the biological lot. The biological-lot price schedule includes indicative quantities of 40 call-out hours, 130 service-engineer labour hours and 65 inspection reports. The tender deadline is 23 November 2026 at 12:00, and bids must be submitted electronically. Price accounts for 60% of the evaluation and quality for 40%; quality covers odour-treatment assessment and optimisation, delivery performance and sustainability. Tenderers must submit the required declarations, reference and price forms, and quality responses. Key suitability requirements include at least one qualifying reference from the previous three years for each lot bid for, valid VCA certification or equivalent, trade-register registration and business liability insurance.