La Rioja updates the environmental authorization of the Agoncillo aeronautical plant

The General Directorate of Environmental Quality, Climate Change and Water of the Government of La Rioja has modified the integrated environmental authorization of the aircraft structural parts machining facility in the municipality of Agoncillo and has approved its consolidated text. The decision is formalized in Resolution 339/2026, signed on September 14, 2026, and published in the Official Gazette of La Rioja no. 179, of September 17, 2026 (reference BOR-A-20260917-III–3560). The change is limited to the waste generated by the plant and nullifies the previous resolutions of the authorization.

The facility belongs to Mecanizaciones Aeronáuticas S.A. and Tratamientos y Procesos Finales Aeronáuticos S.L. and is dedicated to the machining of aluminum, titanium, and steel parts and their subsequent surface treatment for the assembly of units destined for the aeronautical industry. The activity is included in category 2.6 of Annex I of Legislative Royal Decree 1/2016, of December 16, and is therefore subject to integrated environmental authorization; the processed file is IPPC 24/AAI 23-2025.

The original authorization was granted via Resolution 418, of June 6, 2007 (file IPPC 24/AAI 05-2006), and has since accumulated successive revisions:

• Resolution 231, of May 9, 2008 (file IPPC 24/AAI 03-2008).
• Resolution 240, of June 13, 2013 (file IPPC 24/AAI 09-2013).
• Resolution 387, of December 17, 2013, for updating (file IPPC 24).
• Resolution 42, of February 24, 2016 (file IPPC 24/AAI 01-2016).
• Resolution 13/2020, of January 16 (file IPPC 24/AAI 17-2016).
• Resolution 15/2024 (file IPPC 24/AAI 18-2023) and Resolution 256/2024, of June 28 (file IPPC 24/AAI 08-2024).

On July 25, 2025, the company requested a non-substantial modification of the authorization to change the waste produced. After verifying compliance with article 14 of Royal Decree 815/2013, of October 18, and following the hearing process without allegations, the environmental body classified it as a non-substantial modification.

A machining and surface treatment plant

The process begins with milling machines that use synthetic oils as lubricating and cooling fluids, followed by a deburring process to remove burrs and clean remaining cutting fluid. The plant has two silos with a unit capacity of 20,000 kilograms to store chips with cutting fluid, with separation by decantation.

Subsequently, a dimensional inspection and surface treatment are performed, which include alkaline degreasing, pickling, anodizing, and sealing, and conclude with spray painting in three booths. Industrial waters are purified through the reduction of chromium (VI) to chromium (III), neutralization, flocculation, and decantation, and the treatment tanks feature gas collection and a scrubber for neutralization.

The single text establishes the registration numbers of the facility:

• IPPC reference number: IPPC 024.
• Potentially atmosphere-polluting activity: MAA/000166.
• Production of hazardous waste: 17P01010000000018.
• Production of non-hazardous waste equal to or greater than 1,000 tons per year: 17P03220000000046.
• Potentially soil-polluting activity: 17PCS230000000924.

Twenty-two sources and emission limits

Annex I of the resolution inventories 22 atmospheric emission sources, including paint booths, drying ovens, silos, shot blasters, the wastewater treatment plant, and two gas boilers. The boiler at Source 8 is an IGNYS WA-1000 of 1.163 MWt and that of Source 22 is a VULCANO SADECA EUROBLOC SÚPER AS 1500 of 1.744 MWt; both are medium combustion plants and, as of January 1, 2030, must comply with Article 6 of Royal Decree 1042/2017, of December 22.

For the gas scrubber (Source 10), emission limit values are established at 50 mg/Nm³ of NOX, 2 mg/Nm³ of hydrogen fluoride, 25 mg/Nm³ of hydrogen chloride, 10 mg/Nm³ of SOX, 0.2 mg/Nm³ of total chromium, and 30 mg/Nm³ of particles. In sources 13, 14, 18, 20, and 21, the particle limit is 30 mg/Nm³, with monitoring every five years, and measurements for Source 22 must be carried out by authorized control bodies during 2026.

Waste, discharges, and monitoring

Annex II details the hazardous and non-hazardous waste by process, with their EWC codes and the planned treatment operations. Storage is limited to six months for hazardous waste, extendable by another six months in justified cases, and to two years for non-hazardous waste intended for recovery and one year if intended for disposal.

The holder must maintain a chronological file for at least five years, submit a summary report before March 1 of each year, and present an annual operational report within the first three months following the analyzed fiscal year. Discharges to the municipal sewage network shall comply with Law 5/2000, of October 25, with a quarterly logbook of pH, suspended solids, chemical oxygen demand, conductivity, total chromium, cadmium, aluminum, zinc, nickel, tin, iron, copper, and lead.

The resolution, which is forwarded to the company and to the Waste Management and Control and Environmental Integration services, provides for the review of conditions within a period of four years from the publication of the sector’s best available techniques conclusions.

The update provides legal certainty to an industrial facility located in Agoncillo and establishes in writing the environmental obligations it must comply with regarding emissions, discharges, and waste, a matter of direct interest to the municipality and to the aeronautical sector of La Rioja.

Source: Official Gazette of La Rioja, no. 179, September 17, 2026, III. Other Provisions and Acts, pages 16068-16082 (official reference: BOR-A-20260917-III–3560).