Md 73 Quartz Mountain, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 4.9 ppb (monitoring period 2024-2026). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
About Md 73 Quartz Mountain
Md 73 Quartz Mountain serves about 375 people through 127 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Madera County, California. EPA system ID: CA2000690; phone on file: 559-675-7820. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
Against the period ending 2023 (5 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Md 73 Quartz Mountain is 7 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 4.9 ppb |
| 2023 | 5 ppb |
| 2020 | 3.7 ppb |
| 2017 | 7 ppb |
How Md 73 Quartz Mountain compares
Of the 2,884 California systems with a lead result, the median latest reading is 0 ppb; 30 are over 15 ppb right now and 215 have gone over at some point. Md 73 Quartz Mountain's 4.9 ppb sits at the 91st percentile in California and the 90th nationally (higher means more lead).
Other water systems in Madera County
67 other systems share Madera County; 11 of them have a higher latest lead result than Md 73 Quartz Mountain. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| City Of Madera | 66,560 | 3 ppb |
| Chowchilla City Water Dept | 13,916 | 0 (not detected) |
| Riverstone/Rootcreek Water District | 10,276 | 1.2 ppb |
| Madera Valley Water Company | 6,524 | 0 (not detected) |
| Yosemite Spring Park Util Co | 5,300 | 0 (not detected) |
| Tesoro Viejo Master Mwc, Inc. | 4,660 | 0 (not detected) |
| Cal Am - Oakhurst | 3,710 | 5 ppb |
| Valley State Prison | 3,151 | 0 (not detected) |
| Madera Co Md10a-Madera Ranchos | 3,072 | 5.4 ppb |
| Cal Am - Bass Lake | 3,066 | 2 ppb |
Next steps for Madera, CA
Test your own tap with a certified lab first-draw sample; Madera, CA may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Md 73 Quartz Mountain whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. The lead result guide covers how utilities pick the homes they sample. The action level is dropping - the 10 ppb rule from 2027.