Carlsbad Unified School District

Independent Investigation of Carlsbad's Hope Elementary School Water Cross-Contamination Finished

The independent investigation was prompted by an outside legal counsel retained by Carlsbad Unified School District

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An independent investigation into the cross-contamination reports at Hope Elementary reported multiple times during the last year has been completed and is expected to be presented to community members Wednesday evening.

The investigation was conducted by Carl Botterud, described by the Carlsbad Unified School District (CUSD) as an independent attorney and workplace investigator, was hired in late March 2022, by an external legal firm that had been hired by CUSD.

According to a report published by CUSD, in advance of Wednesday evening's school board meeting, it was determined that a cross-connection occurred between Hope Elementary School's reclaimed water and potable water systems, "behind classroom 35" in August 2021.

During the course of the investigation, Botterud interviewed 44 witnesses, including 28 Hope Elementary School staff members, two parents, a friend of a teacher, and several district staff members.

The manager of Erickson-Hall Construction, who was overseeing the ongoing construction project at the school as well as the project's architect, were also interviewed.

CUSD says that Botterud requested interviews with employees of Interpipe, a plumbing contractor hired by Erickson-Hall, however, the questions sent to the contractor were answered via email only.

Erickson-Hall shared a statement with NBC 7 regarding the outcome of the investigation, it reads:

"When complaints arose over the smell and taste of the water at Hope Elementary School, we immediately engaged with the Carlsbad Unified School District to investigate the cause.  After repeated testing, it was determined that a potable water line and recycled water line had been connected, leading to water contamination within certain parts of the school. 

Per Erickson-Hall’s investigation to this point, we believe that the individual who connected the potable and reclaimed water lines did not know that they were doing anything wrong, because the reclaimed water pipe (which was already installed on the campus) was not properly identified as one which carries reclaimed water.  Erickson-Hall was not contracted to work on the reclaimed water system at Hope Elementary.  We did not direct the plumbing contractor to touch the pipe in question; nor do we know who connected it or why.  We continue to work closely with Carlsbad Unified School District to further investigate."

Investigation Timeline


2018: The modernization project at Hope Elementary School begins

August 2020: The Carlsbad Municipal Water District recommends to CUSD that the school's irrigation system be "highlined" from recycled water to potable water. According to the report, CUSD agreed to this recommendation.

“Highlining” an irrigation system takes place when a potable source of water is connected to the recycled water system temporarily for testing purposes

September - November 2020: The City of Carlsbad would not issue various work permits, including that for the installation of the temporary water meter to highline the irrigation system to a stop work order that had been issued over grading problems.

Summer 2021: Construction work resumes at the Hope Elementary campus including the removal of a temporary classroom and painting of other classrooms.

On August 24, 2021, students at Hope Elementary returned to campus. Early that day, Hope's principal advises that water to "Room 35" is off. Later that day, a representative of Erickson-Hall construction replies that the water had been fixed in this classroom. A cross-connection linking reclaimed water into the potable water system is located at the back of Room 35. A flexible copper hose linking the two was not painted, indicating it was installed after the classrooms were painted.

At various points throughout September and October 2021, multiple verbal reports from "limited locations," most often in the restroom near the school's STEAM lab, that there was discolored, foul-smelling and bad-tasting water.

On November 8, 2021, a teacher emailed Hope's principal to reiterate concerns previously raised after the water quality. This prompted water quality testing samples to be collected by Erickson-Hall Construction. Erickson-Hall reports that the water was safe to drink, as there was no presence of harmful bacteria.

Throughout November, there were continued reports of discolored, foul-smelling and bad-tasting water.

December 15, 2021: New water samples were drawn by Interpipe for analysis by EnviroMatrix, a water quality testing and consulting company, according to CUSD. These results were analyzed and sent to Erickson-Hall on January 11, 2022.

On February 8, 2022, Hope’s principal received more reports of water quality concerns.

NBC 7's Dave Summers heard from parents who want the school district to do more to make sure students aren't suffering long-term impacts from drinking contaminated water.

February 9, 2022: Erickson-Hall sent test results to CUSD, stating that “the water is within safe standards for safe drinking water," however the results showed the presence of trace metals, specifically copper, in quantities above reporting levels. The same day, Erickson-Hall, suggested multiple possible causes of intermittent water discoloration. 

February 14, 2022: EnviroMatrix is formally contracted by the District to perform an onsite inspection at Hope Elementary. The testing was scheduled by EnSafe for February 24 (following Presidents’ Weekend).

February 24, 2022: EnviroMatrix conducts its testing and analysis. The same day, Erickson Hall notifies Carlsbad Municipal Water District that a cross-connection had occurred. The cross-connection to recycled water is located and the school is closed.

March 28, 2022: Botterud is hired to conduct an investigation

March 29, 2022: CUSD notifies Hope Elementary parents and staff of the investigation.

The investigation resulted in four conclusions:

  • Each time a concern was reported to the Principal, she reported it to the District Bond Program Manager and Erickson-Hall construction.
  • District staff relied on the contractors' assertions that the water was safe, based on the testing that was performed.
  • Based on the information received in February, the District was led to hire its own consultant to determine the cause of the problem.
  • Erickson-Hall eventually mitigated and repaired the condition and confirmed there were no other cross-connections.

The report outlines fifteen protocol changes ranging from an increase in school board oversight to a direction for school staff to receive concerns and share them with district officials.

It also highlights a need to make staff and parents aware of the "Williams" complaint process, a process that resulted from a ruling in a 2000 ACLU lawsuit regarding the deteriorating conditions of California's public schools.

The timeline and protocol changes will be presented as part of CUSD’s regularly scheduled school board meeting Wednesday night.

The meeting will take place in the Performing Arts Center at Sage Creek High School in Carlsbad, beginning at 6:00 p.m.

A copy of the report's timeline and outcomes, as published by CUSD can be read below.

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