How Susanville tests the city’s drinking water for lead and copper

Safe drinking water depends on regular monitoring from the source through the distribution system and, in some cases, inside a customer’s plumbing. The City of Susanville Public Works Department tests for lead and copper because these metals can enter water after it leaves the treatment or supply system, particularly when water remains in contact with older fixtures, solder, or service line materials.

Lead and copper are not usually detected by looking at the water. Certified laboratory analysis is required, and the sampling process must be carefully controlled so results reflect normal household exposure. The City uses regulatory sampling procedures, documented chain-of-custody practices, and quality controls to produce reliable information for residents and state drinking water officials.

Residents can find utility information, conservation resources, contacts, and infrastructure updates through the Public Works website. Water quality monitoring is one part of the department’s broader responsibility for maintaining dependable public services and protecting community health.

Why lead and copper are monitored

Lead can affect the nervous system and is especially concerning for infants, children, and pregnant people. Copper is an essential mineral in small amounts, but elevated levels may cause gastrointestinal discomfort and can indicate corrosion within plumbing. Neither metal is expected to be added intentionally to drinking water; they typically enter through contact with plumbing materials.

The city’s water system is managed to reduce corrosion, and routine testing helps verify that those controls are working. Sampling also helps identify whether certain homes, neighborhoods, or plumbing configurations require additional evaluation. The goal is prevention: finding conditions that could contribute to metal exposure before they become a larger public health concern.

Federal and California drinking water rules establish how public water systems select locations, collect samples, use certified laboratories, and report results. The number and type of samples can vary according to the system’s size, monitoring history, and regulatory schedule.

Where the samples come from

Lead and copper samples are generally collected at customer taps rather than only at a treatment facility. A source-water sample can show the quality of water entering the distribution system, but a tap sample is more useful for evaluating metals that may be released by household plumbing.

The City may select residences or other buildings using an inventory of plumbing materials and previous monitoring data. Priority is typically given to locations that may represent higher-risk materials, such as lead service lines, lead solder, or older faucets. Participating residents receive instructions so their samples meet the required protocol.

A representative sample is important. Testing only a newly renovated home or only a location with modern plumbing would not provide a complete picture of potential exposure across the service area. Sampling locations are therefore chosen to reflect the conditions regulators require the utility to monitor.

How a sample is collected

Lead and copper monitoring commonly uses a first-draw sample. The selected cold-water tap is not used for a specified period, often at least six hours, allowing water to remain stationary in the plumbing. The sample is then taken without flushing the tap first. This method measures the water that has had the longest contact with interior plumbing.

Sampling instructions may include using a kitchen or bathroom cold-water faucet, removing or avoiding a faucet aerator when directed, and filling the provided bottle carefully. Residents should not run water, wash dishes, do laundry, or use the selected tap during the stagnation period. If the procedure is not followed, the result may not be comparable with other compliance samples.

The bottle is labeled with the location and collection time, then returned according to the department’s instructions. Documentation protects the sample’s identity and condition from collection through laboratory analysis.

How results are evaluated

Samples are sent to a laboratory certified to analyze drinking water for lead and copper. The laboratory uses sensitive methods to measure concentrations, records quality-control data, and reports results in units such as parts per billion for lead and parts per million for copper. The department reviews the laboratory report for completeness and compares the findings with regulatory requirements.

Measure	What it helps show	Typical regulatory reference
Lead concentration	Whether lead may be entering water from plumbing or service materials	15 parts per billion action level
Copper concentration	Whether corrosion may be releasing copper into drinking water	1.3 parts per million action level
90th percentile	The result used to evaluate the group of compliance samples	Based on the highest results after excluding the top 10 percent
Follow-up monitoring	Whether additional sampling or corrosion-control steps are needed	Determined by results and state or federal requirements

The 90th percentile is used because lead and copper concentrations can vary substantially from one tap to another. An isolated high result matters and should be investigated, but the regulatory determination considers the distribution of results across the required sample set.

An action-level exceedance does not mean every tap in the city has the same concentration. It does mean the water system must take specified steps, which may include additional monitoring, public notification, corrosion-control review, customer education, or infrastructure assessment.

What happens after testing

Public Works staff review results with the applicable drinking water regulator and look for patterns. A single unusual result may prompt confirmation or investigation of the sampling location, while repeated elevated results can lead to a broader evaluation of plumbing materials and treatment practices.

Residents whose homes are selected for monitoring should follow the instructions closely and report problems with the faucet, sample bottle, or collection schedule. A sample from one property cannot determine conditions at every other property, so clear location information is essential to interpreting the data.

If a regulatory response is required, the City communicates the appropriate information through official notices and water quality updates. Residents should rely on those sources for verified results rather than assuming that water appearance, taste, or odor can reveal lead or copper levels.

Steps that support accurate monitoring

Good household practices can help reduce exposure while testing and follow-up work continue. They also make it easier for the City to collect dependable samples.

• Use only cold tap water for drinking, cooking, and preparing infant formula; heat water after drawing it if needed.
• Let water run briefly after a long period of nonuse, following current Public Works guidance, before filling a drinking container.
• Never use hot tap water to prepare food or beverages because hot water can dissolve metals more readily.
• Keep sampling appointments and follow every stagnation and collection instruction provided by the department.
• Contact Public Works before replacing a service line or plumbing component if you need information about approved materials or available guidance.

Water safety also fits into broader household preparedness. Residents reviewing the City’s wildfire smoke guidance can organize emergency supplies and official contact information alongside routine utility resources.

The City’s drinking water monitoring program depends on sound laboratory methods, representative locations, and resident cooperation. Check official Public Works updates for current sampling information, report water concerns through the department’s published contacts, and use verified city and regulatory notices when making decisions about household drinking water.