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Explorer Well Project

A piece of equipment at a well


Pasadena Water and Power (PWP) will be constructing a new water well - Explorer Well.  This well, when combined with PWP’s other four existing wells in the Arroyo, will further assist in the groundwater cleanup operations.

Water pumped from Explorer Well will be treated at the Monk Hill Treatment System to provide clean and safe drinking water.  A new concrete masonry unit building will house the well along with the associated mechanical components and electrical equipment for security and sound attenuation. A perimeter chain link fence will be installed for site security and PWP staff access.


The proposed location for the Explorer Well is in the former JPL East Parking Lot, approximately 2,500 feet north of the intersection of Windsor Avenue and Ventura Street.  The existing roadway will be realigned prior to the commencement of the above grade improvements for Explorer Well.

A map of the explorer well site layout on Explorer Rd.


  • Public Outreach: PWP presented the project to the Hahamongna Watershed Park Advisory Committee on July 24, 2018, and provided an update on September 26, 2023.
  • Design: The below-grade design is anticipated to be completed by February 2024, and the above-grade design is anticipated to be completed by April 2024.
  • Initial Study/Mitigated Negative Declaration (MND):  This document, in compliance with the California Environmental Quality Act, will be completed and circulated for public review and comments in February 2024 for 30 days. To review the Initial Study/Mitigated Negative Declaration, please click here.
  • Construction: Construction of below-grade improvements is anticipated to begin by July 2024 and completed by December 2024. Construction for the above grade improvements is anticipated to begin by January 2025 and completed by January 2026.

Construction Hours

During the below grade improvements, drilling the well non-stop (24 hours/day) will be necessary for the entire well depth to avoid collapse of the borehole.  The non-stop drilling operations is anticipated to  occur in two 20-day continuous work phases with a 2-week downtime in between.  However, the actual duration may change due to unforeseen conditions.  After the well drilling is completed, subsequent tasks will be performed Monday through Friday, 7 a.m. – 7 p.m.

After the below grade improvements are completed, construction activities will be minimized until the next and final phase begins which will involve the above grade improvements.

Additional Information

PWP will implement the necessary measures to mitigate noise levels, ensure public safety around the work area at all times, and special efforts will be taken to keep any other inconveniences to a minimum during construction.

Contact Information

For questions, contact Johnathan Giang, Engineer, at