What Los Angeles Residents Should Know
Los Angeles water comes primarily from three sources: the Los Angeles Aqueduct (Eastern Sierra Nevada), the State Water Project (Northern California), and the Colorado River Aqueduct. The city also uses local groundwater for about 10-15% of its supply. This complex water system faces several challenges:
The most common water quality issue in Los Angeles is hard water, which contains high levels of minerals like calcium and magnesium. While hard water is generally safe to drink, it can cause plumbing issues, affect appliance lifespans, and leave residue on dishes and laundry.
Drought conditions in recent years have increased the concentration of certain contaminants in water sources. Although LADWP treats water to meet all federal and state standards, some neighborhoods, particularly those with older infrastructure, may experience water quality variations.
Key Water Quality Issues
These are the primary water quality concerns affecting Los Angeles residents.
Hard Water
Common IssueSource: Natural minerals (calcium and magnesium) from water sources
Effects: Scale buildup in pipes and appliances, soap scum, spotty dishes, stiff laundry
LA Levels: 12-18 grains per gallon (205-308 mg/L), considered "hard" to "very hard"
Health Concerns: None; hard water is safe to drink but can cause household inconveniences
Chromium-6
Below State LimitsSource: Industrial contamination, natural deposits
Health Effects: Potential carcinogen with long-term exposure
LA Levels: Average 0.04-0.2 ppb, below California's standard of 10 ppb
Regulation: California has stricter standards than federal EPA
Total Dissolved Solids (TDS)
ElevatedSource: Mineral content from imported water and groundwater
Effects: Affects taste, can contribute to hard water issues
LA Levels: 350-600 mg/L, higher during drought periods
EPA Limit: Secondary standard of 500 mg/L (aesthetic guideline, not health-based)
Taste and Odor Issues
Aesthetic OnlySource: Chloramine disinfection, seasonal algae, and mineral content
Effects: Temporary chlorine smell or earthy taste
Concerns: Aesthetic only, not a health risk
Solutions: Refrigerating water, using carbon filters
Neighborhood Variations
Water quality can vary across Los Angeles neighborhoods based on water source, infrastructure age, and elevation.
Water Quality by Region
| Area | Primary Water Source | Hardness Level | Infrastructure Age | Notable Issues |
|---|---|---|---|---|
| San Fernando Valley | Groundwater + MWD | Very Hard (15-18 gpg) | Mixed | Higher mineral content, some historical contamination issues |
| Central LA | MWD Blend | Hard (12-15 gpg) | Older | Aging pipes in some neighborhoods |
| West LA / Santa Monica | MWD Colorado River | Hard (13-16 gpg) | Mixed | Higher TDS levels |
| South LA | MWD Blend | Moderately Hard (10-14 gpg) | Older | Some areas with aging infrastructure |
| East LA | Groundwater + MWD | Hard (12-15 gpg) | Varied | Some areas with higher mineral content |
| Hollywood Hills / Higher Elevations | MWD Blend | Hard (12-14 gpg) | Mixed | Pressure issues, occasional discoloration |
MWD = Metropolitan Water District of Southern California
gpg = grains per gallon (measure of water hardness)
Drought Impact on Water Quality
California's ongoing drought conditions affect Los Angeles water quality in several ways.
Increased Mineral Concentration
During drought periods, water sources contain higher concentrations of naturally occurring minerals like calcium and magnesium, leading to harder water.
This can increase scale buildup in pipes and appliances and make soap less effective.
Taste and Odor Changes
Lower reservoir levels combined with higher temperatures can contribute to algae growth in source waters, which may cause earthy or musty tastes and odors.
While not harmful, these temporary aesthetic issues are more common during drought conditions.
Source Water Changes
During severe drought, Los Angeles may rely more heavily on certain water sources over others, which can change the mineral profile and treatment requirements.
This sometimes results in noticeable differences in water characteristics.
Treatment Adjustments
LADWP may need to adjust water treatment processes during drought conditions to address changing water quality in source waters.
While the water remains safe to drink, these adjustments may temporarily affect taste or smell.
Recommended Action Steps
Based on Los Angeles water quality data, we recommend these actions to protect yourself and your family.
Consider a Water Softener for Hard Water
If you're experiencing significant hard water issues (scale buildup, spotty dishes, dry skin after showering), a water softener can effectively reduce mineral content. Whole-house systems are most effective, while point-of-use systems can treat water at specific fixtures.
Use a Carbon Filter for Taste and Odor
To improve taste and reduce chlorine odors, a simple carbon filter (pitcher, faucet-mounted, or under-sink) is effective. Look for NSF/ANSI Standard 42 certification for chlorine reduction.
Flush Taps After Water Service Disruptions
After water main repairs or service disruptions, run cold water for 3-5 minutes to clear any sediment or air that may have entered the lines. Start with the lowest faucet in your home and work upward.
Maintain Water Heaters More Frequently
Hard water causes more rapid sediment buildup in water heaters. Consider flushing your water heater annually, rather than the standard recommendation of every 2-3 years, to extend its lifespan and improve efficiency.
Check Older Homes for Lead Plumbing
Homes built before 1986 may have lead solder in plumbing. If you live in an older home, have your water tested for lead, especially if you have young children. Lead is especially harmful to children's developing brains and nervous systems.
Adjust Cleaning Practices for Hard Water
Use cleaning products designed for hard water areas, reduce soap and detergent amounts (concentrated formulas can leave more residue), and consider using vinegar to remove mineral buildup on fixtures and appliances.
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