The purpose of this procedure is the execution of all the works and supplies necessary for the realization of the intervention PNRR-M2C4-I4.1-A2-7 - Reconstruction of the adductors of the Algua aqueduct. Lot 1: Reconstruction of the second pipeline of Algua. The contract works include the reconstruction of the II Algua pipeline for the conveyance of water derived from the Algua spring in the stretch that goes from the Ventolosa chamber to the S. Agostino reservoir in upper Bergamo for a total length of about 9 km.

The contract works include the reconstruction of the II Algua pipeline for the conveyance of water derived from the Algua spring in the stretch that goes from the Ventolosa chamber to the S. Agostino reservoir in upper Bergamo for a total length of about 9 km.

The new adductor will be realized by laying steel pipes for butt welding, external polyethylene coating and internal epoxy paint.

Below are the homogeneous features of the new adductor referring to the technical and graphic drawings for all the necessary insights.

- Section 1 from Ventolosa to the bridge over the Gaggio canal – DN 800

- Section 2 from the bridge over the Gaggio canal to via Ripa – DN 700

- Section 3 along Via Ripa – DN 800

- Sections 4 and 5 along via Prada and via Aldo Moro up to the Rino chamber – DN 800

- Tract 6 – Camera del Rino – DN 800

- Sections 7 and 8 along via Aldo Moro and via Brughiera – DN 800

- Section 9 along the SP n. 470 – DN 800

- Section 10 along Via Olimpia – DN 800

- Section 11 from via Olimpia to the south ring – DN 800 – DN 700 at the crossing of the TEB

- Section 12 - Stretch from the southern ring to the crossing of the Quisa stream

- Section 13 - Crossing the Quisa Stream - DN 700

- Section 14 – Cycle path inside the Parco dei Colli di Bergamo – DN 700

- Section 15 – from the cycle path to the Macazzolo tunnel – DN 700

- Section 16 – Section inside the Macazzolo Gallery – DN 700

- Section 17 - Stretch from the Macazzolo tunnel to the Macazzolo chamber – DN 700

- Section 18 – Camera del Macazzolo – DN 700

- Section 19 - Stretch from the Macazzolo chamber to via Castagneta – DN 700

- Section 20 - from via Castagneta to the top of the hill - DN 600

- Section 21 - From the top of the hill to via Valverde – DN 600

- Section 22 - Stretch along Via Valverde – DN 600

- Section 23 -24 - Stretch along Via Maironi – DN 600

- Section 25 - Section in the green area between the walls of upper Bergamo – DN 600

- Section 26 - Section in the tunnel crossing the walls of upper Bergamo – DN 600

- Section 27 -28 - Stretch along Via della Fara to the reservoir of S. Agostino – DN 600

- Section 29 - Section inside the entrance gallery S. Agostino

In addition to the renovation of the second pipeline, a series of interventions are planned to allow the correct functioning of the distribution network during the decommissioning of the various sections of the second pipeline subject to reconstruction. Especially:

- n.1 connection of the existing network pipes along via Brughiera through the supply and installation of steel pipes DN 100 and relative cutting gate;

- n.2 connections of the existing network pipes along the SP n. 470 by supply and installation of steel pipes DN 100 and n. 2 cutting gate for each connection.

- n.1 connection of the existing network pipes along Via Monte Bianco through the supply and installation of steel pipes DN 125 and relative cutting gate;

- temporary and subsequently definitive connection of Quadrifoglio users along the second adductor section planned along the cycle path of the Parco dei Colli di Bergamo;

- n.1 connection of the existing network pipes along Via Castagnea through the supply and installation of steel pipes DN 100 and relative cutting gate;

- Realization of a pressure reduction product and subsequent connection of the same by pipe in steel DN 100 along Via Castagneta;

- Construction of a new DN 100 steel distribution section with a length of about 240 m along Via Valverde and subsequent connection of the same to the utilities currently served by the II pipeline.

For a detailed description, please refer to the Special Tender Specifications (hereinafter CSA) and to the technical and graphic documents.