Understanding VOCs in Cleveland County Water: Seasonal Changes and System Records

This week, you need to decide whether seasonal changes could be influencing the presence of volatile organic compounds (VOCs) in your household water supply and how to interpret water quality records for Cleveland County, Oklahoma.

How Seasonal Water-Table Changes Move a Solvent Plume Relative to a Well Screen

Water tables fluctuate naturally throughout the year due to rainfall, drought, and groundwater recharge rates. These seasonal changes can affect the position of a plume of VOCs—solvent compounds that may migrate underground. When the water table rises, the plume can move closer to a well screen that draws water, increasing the chance of VOCs entering the supply. Conversely, a lower water table might move the plume away, reducing potential exposure. Understanding these movements is essential because they influence when VOCs may be more or less detectable in water drawn from wells or municipal connections.

Which Volatile Organic Compounds Appear in This Record and Which Do Not, Named From the Facts

The public water system serving Cleveland County, specifically the Norman system (OK1020801), uses surface water and serves over 104,000 people. Between 2013 and 2015, federal monitoring detected no levels above reporting thresholds for several measured VOCs including 1,1-dichloroethane, chloromethane, bromomethane, HCFC-22, Halon 1011, 1,3-butadiene, and MTBE. Each VOC was measured multiple times with no detections above the respective instrument sensitivity, expressed in micrograms per liter (µg/L) or parts per billion (ppb). This indicates that in these samples, these particular volatile solvent compounds were either absent or below detectable concentrations. It is important to note that detection does not necessarily imply a violation or unsafe condition, as there are no federal maximum contaminant levels (MCLs) defined for these compounds under this monitoring rule.

Which Fixtures, Appliances or Processes Are Affected First and Why

VOCs are volatile, meaning they tend to evaporate easily at room temperature. In a household, this means that fixtures and appliances involving water heating or aeration may release VOCs into the air or concentrate them in water if present. For example, showers and hot water systems can release solvent vapors from water, potentially noticeable as unusual smells. Ice makers and drinking water taps could also deliver water containing VOCs, though typically in very low amounts if present. Appliances that filter or treat water can reduce VOC levels where equipped with suitable technology. Recognizing which parts of your home water use might be impacted helps in assessing symptoms and considering treatment options.

How to Compare This Area's Record With a Neighboring County's Without Overreading It

When comparing the VOC monitoring results of Cleveland County to those of an adjacent county, be aware that each water system may have different sources, sampling methods, and detection limits. A zero detection in one county does not guarantee the same for another, nor does a detection imply widespread presence in the whole area. Differences in geological conditions, water sources (surface water vs. groundwater), and system management all influence VOC levels. Therefore, comparisons should be cautious and focused on understanding broad trends rather than making assumptions about individual home water quality.

The Household or Facility Symptoms That Do and Do Not Point to This Problem

If you notice unusual tastes or odors, especially chemical or solvent-like smells during showering or from hot water, this could indicate VOC presence in your local water supply. However, some symptoms such as discoloration, scaling, or health symptoms unrelated to volatile compounds typically do not point to VOC issues. Remember, only specific water testing of your household supply can confirm VOC levels. Symptoms might result from other water quality factors not related to volatile organics. Careful observation combined with testing is the best approach to identifying if solvents may be affecting your household water.

In summary, the Cleveland County water system’s government monitoring records represent measurements taken for the public water supply, not individual household water. They show no detections above reporting levels for a key group of VOCs. To understand your own water’s condition, specific testing is needed. For households concerned about volatile organic compounds, products like the C-Series VOCs & Industrial Chemicals Filter ship ready to configure and offer a documented approach to reducing volatile solvent chemicals from water.

For more detailed information, visit the EPA’s Safe Drinking Water Information System (SDWIS) public water system records at epa.gov/dwucmr.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2014-02-11. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Norman (OK1020801), OK: 353 results across 7 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level