Lead Pipe Map

California · 24 community water systems

Lead pipes in San Mateo County, CA

24 community water systems serving San Mateo County reported 0 lead and 19 galvanized-requiring-replacement service lines, plus 25,818 of unknown material. The most are in Portola Improvement Association MWC.

<0.1% of these systems' lines are lead or galvanized requiring replacement, lower than the California average (0.1%) and lower than the national average (3.1%).

0Lead
19Galvanized, replace
25,818Unknown
178,913Non-lead

Water systems serving San Mateo County

Water systemLeadGalv.Unknown% leadPeople
Portola Improvement Association MWCSan Mateo County019056%80
California Water Service-S San FranciscoSan Mateo County0015,4460%62,609
California Water Service - San CarlosSan Mateo County0010,0760%34,801
Cuesta la Honda Guild INCSan Mateo County002960%863
California Water Service - San MateoSan Mateo County0000%103,536
City of Daly CityDaly City0000%102,593
City of Redwood CityRedwood City0000%90,043
California Water Service - Bear GulchSan Mateo County0000%60,382
City of San BrunoSan Bruno0000%42,631
North Coast County Water DistSan Mateo County0000%38,546
Estero Municipal Improvement DistrictSan Mateo County0000%36,556
City of BurlingameBurlingame0000%32,453
Mid-Peninsula Water DistrictSan Mateo County0000%31,059
City of East Palo AltoEast Palo Alto0000%29,519
City of MillbraeMillbrae0000%22,795
Menlo Park Municipal WaterMenlo Park0000%22,362
Coastside County Water DistrictSan Mateo County0000%19,033
Westborough Water DistrictSan Mateo County0000%13,486
Town of HillsboroughSan Mateo County0000%11,766
Montara Water and Sanitary DistrictSan Mateo County0000%6,088
City of BrisbaneBrisbane0000%3,434
Palo Alto Park Mutual Water CompanySan Mateo County0000%2,900
O'Connor Tract Co-Operative Water Co.San Mateo County0000%2,789
Guadalupe Valley MidSan Mateo County0000%1,455

Systems that also serve other counties are counted in full. Your water bill names your utility.

What to do if your line is lead or unknown

  1. Check the pipe where water enters your home.
  2. Use a filter certified to NSF/ANSI 53 for lead for drinking and cooking.
  3. Test your water, often free through the utility.
  4. Ask your utility about free or discounted replacement; most lines must be replaced by December 31, 2037.

Check another water system

Questions

Does San Mateo County have lead pipes?

Yes. Water systems serving San Mateo County reported 0 lead and 19 galvanized-requiring-replacement service lines, plus 25,818 of unknown material.

Which San Mateo County water systems have the most lead lines?

Portola Improvement Association MWC (19).

How do I check my home in San Mateo County?

Find the water system named on your water bill in the table above, open its page and use its address-level inventory. You can also scratch-test the pipe where it enters your home.