Water Quality Project Sampling Strategy

Background

Lead in water distribution systems has been increasingly regulated over time, but old plumbing components, with the potential to release lead into drinking water, are still ubiquitous across the United States.

Lead concentrations in water distribution systems depend on several factors, including water source, pH, mineral content, and the water’s interaction with plumbing components. Specific sources of lead contamination in drinking water may include:

  • Lead pipes in building plumbing: Dull gray in color and will appear shiny when scratched. Banned since 1986 and not widely used since the 1930s.
  • Copper pipes joined by lead solder: Solder will be dull gray in color and will appear shiny when scratched. Banned since 1986 and many communities banned prior to 1986.
  • Brass pipes, faucets, fittings and valves: May contain alloys of lead.
  • Sediments in screens on faucets: Debris from plumbing can collect on screens and may contain lead.
  • Lead pipes in a municipal water system distribution system. San Francisco does not have any known lead pipes in its distribution system water mains. Some lead joints may exist in the distribution system, but none have been used since the 1980s.
  • Municipal water service lines made of lead; although there are no lead water mains in the city, the pipes that carry water from the municipal water system main to the facility and connect with the premise plumbing may contain lead. San Francisco County removed all known lead service lines (over 7,000) in the 1980s.
  • Specific brands of water fountains contain lead components or have lead lined internal water tanks. Since 1988 water fountain components must be lead free; however, older facilities may still have older lead containing models.

 

Sampling Scope

UCSF is not, at this time, sampling for other water contaminants. The presence or absence of lead in water does not necessarily confirm / eliminate the possibility of other contaminants. Water conditions, sampling protocol and analytical methods are specific to the contaminant being investigated. For the purposes of this program, only lead is being considered.

Due to the size and complexity of the UCSF enterprise, the project will be executed in phases. Sampling phases are prioritized on the presence of sensitive receptors (children, patients) and age of the building (older buildings first). The current phase schedule and status is available <here – link to Results section 2.0>

Depending on logistics, phases may additionally be broken into smaller subgroups based on building age and/or proximity to each other. Sampling priority and schedule is subject to change at the direction of the UCSF Leadership Group.

The Scientific Advisory Group that UCSF convened to guide the development and implementation of UCSF’s water testing program recommends that drinking water be tested for lead every 3 to 5 years.

Sampling Locations

Fixtures to be sampled are limited to:

  • Drinking fountains, both bubbler and water cooler style.
  • Water bottle filling stations
  • Break room sinks
  • Food preparation sinks, including the medical center cafeterias and vendor operated restaurants on UCSF owned property
  • Residential kitchen sinks
  • Any sink known to be or visibly used for water consumption

Adverse impacts to user operations and/or access to available drinking water will be minimized whenever possible. Locations with a single source of drinking water will be sampled early in the day. Areas with few drinking water fixtures may be sampled on alternate days to ensure one is available at all times during regular operating hours.

Locations that will not be sampled include:

  • Hot water supply. Due to several factors, The EPA does not recommend drinking water from a hot water tap. The 3Ts sampling protocol specifically excludes hot water locations from sampling. Hot water locations serviced by local heating elements, such as Insta-hots may be included in the sampling evolution.
  • Bathroom sinks
  • Laboratory sinks
  • Utility / custodian sinks
  • Showers
  • Any fixture without a high likelihood for drinking or food preparation

 

General Sampling Evolution Steps

When a water fixture is identified for sampling, end users can expect the following activity:

  1. The identified water fixture is removed from service 8 to 18 hours prior to sampling. Typically, this occurs the evening prior to sampling by placing a bag over the fixture and signage to avoid using the water location until sampling can occur. This does not mean that the drinking water at your fixture is over the Action Level. This isolation step is a requirement of the sampling protocol
  2. The following morning, EHS will sample the location
  3. The bag and sign are removed and the fixture is returned to service
  4. Water Samples are logged on a Chain of Custody and delivered to the analytical lab
  5. Analytical results are issued to UCSF approximately 10 business days after the sampling event
  6. If lab results indicate that water at the fixture is over the Action Level:
    • The fixture is immediately removed from service upon receipt of the results
    • Signage is placed on the fixture
    • If the identified fixture is the only drinking water source for a user group, an alternate source of water will be provided until the mitigation can be implemented
    • Results are posted on the EHS website
    • Mitigation planning begins
    • Communication is provided to end users in the immediate area
    • Mitigation implementation (Each location is evaluated individually. Mitigation / Repairs may take weeks to months, depending on the actions required to return the fixture to below the Action Level)
    • Follow up sampling occurs after repair work is complete
    • UCSF receives results 2-10 days after sampling
    • If the subsequent results are below the Action Level, the fixture is returned to service and signage removed
    • Results are posted on the EHS website
    • In some cases, follow up communication will be conducted
  7. If lab results at a fixture are below the Action Level:
    • Results are posted on the EHS website

Sampling Protocol

Pursuant to this project, UCSF employs several sampling protocols. The primary protocol, UCSF Drinking Water Sampling Protocol (3Ts), is used to assess lead content at the point of use for each drinking water fixture at the university. The others are used as diagnostic tools during mitigation.

UCSF Drinking Water Sampling Protocol (3Ts)

UCSF is following EPA’s guidelines for testing water quality in K-12 schools, as outlined in the agency’s document “3Ts for Reducing Lead in Drinking Water in Schools” because there are no specific guidelines for universities or clinical facilities.

UCSF elected to follow these guidelines on the advice of a UCSF-convened Scientific Advisory Group made up of public health and water quality experts. The EPA guidelines were developed to address the potential for elevated lead levels in drinking water in schools, as children are most susceptible to health effects of lead. In accordance with these guidelines, UCSF will sample and test cold drinking water locations on UCSF-owned property for lead content. Other locations, such as leased properties, may be sampled later, based on recommendations from the Scientific Advisory Group.

In accordance with EPA guidelines, if lead levels from the sampled water drinking water fixtures exceed the “action level” of 20 parts per billion (ppb), corrective actions will be taken.

The general sampling protocol being employed by UCSF is here

Supplemental Water Sampling Protocol

In the event that mitigation efforts fail at a particular location, the University may choose to employ additional sampling techniques to help guide the mitigation effort. The Supplemental Water Sampling Protocol, based on the USEPA’s “Optimal Corrosion Control Treatment Evaluation Technical Recommendations for Primacy Agencies and Public Water Systems” (link: https://www.epa.gov/sites/production/files/2016-03/documents/occtmarch2016.pdf), has been developed in conjunction with SFPUC.

Of great importance is the scale that builds up naturally on the metal surface of plumbing systems. In some cases, lead may be bound up with other compounds such as iron and aluminum. Lead contained in this scale may be released into drinking water by being dissolved, colloidal, or particulate. Pipe scales can be complex and can have layers. The structure and compounds in the existing corrosion scale can influence the effectiveness of corrosion control and/or filtration technologies.

This Supplemental Water Sampling Protocol is intended to identify the presence of scale and the water’s potential for creating scale within the plumbing system. The specific protocol can be found here

Diagnostic Water Sampling

At the discretion of the mitigation team, diagnostic sampling may be requested in order to better characterize the water quality in different parts of the water distribution system or test mitigation ideas in a controlled setting. This may include, but are not limited to:

  • Sampling a specific piece of equipment with multiple filter types attached
  • Sampling the water main as it enters a building
  • Sampling at the wall (angle stop) at a location before the water enters a particular fixture

These results from these types of samples are reported to the mitigation team, but are not reported on the water project website, as they do not reflect concentrations at the fixture or point-of-use.