Title 22 Chapter 15: Domestic Water Quality & Monitoring — Quick Reference
CA-Specific MCLs (More Stringent Than Federal)
| Contaminant | CA MCL | Federal MCL | Notes |
|---|---|---|---|
| Perchlorate | 0.006 mg/L | None | CA-only regulated contaminant |
| Hexavalent Chromium | 0.010 mg/L | None (total Cr only) | CA-only MCL |
| 1,2,3-TCP | 0.000005 mg/L | None | CA-only, extremely low DLR |
| Fluoride | 2.0 mg/L | 4.0 mg/L | CA is twice as stringent |
| Barium | 1.0 mg/L | 2.0 mg/L | CA is twice as stringent |
| Arsenic | 0.010 mg/L | 0.010 mg/L | Same as federal |
| Nitrate (as NO3) | 45 mg/L (= 10 mg/L as N) | 10 mg/L as N | Same, different units |
| Nitrite (as N) | 1 mg/L | 1 mg/L | Same as federal |
Federal vs. California: Three contaminants regulated by California have no federal MCL at all: perchlorate, hexavalent chromium, and 1,2,3-TCP. Two others (fluoride and barium) have California MCLs that are half the federal limit. If you studied with federal materials, you may not know these contaminants are regulated in California or may have the wrong numbers. The T-5 exam tests CA-specific MCLs directly.
Radioactivity MCLs
Combined Radium-226 & -228: 5 pCi/L. Gross Alpha (excluding radon & uranium): 15 pCi/L. Uranium: 20 pCi/L. Beta/photon emitters: 4 millirem/year.
Secondary Standards
| Parameter | Standard | Notes |
|---|---|---|
| Iron | 0.3 mg/L | Aesthetic, but enforceable in CA |
| Manganese | 0.05 mg/L | Aesthetic, but enforceable in CA |
| Color | 15 units | |
| Odor | 3 threshold units | |
| TDS | 500/1,000/1,500 mg/L | Recommended/Upper/Short-term |
| Aluminum | 0.2 mg/L |
Federal vs. California: At the federal level, National Secondary Drinking Water Regulations (NSDWRs) are non-enforceable guidelines. In California, secondary standards under §64449 carry enforcement weight. That's one of the most commonly tested federal/CA divergences on the T-5 exam. An operator who studied federal materials will assume secondary standards are advisory. In California, they are not. Source: Title 22 §64449 vs. 40 CFR 143.
Facility Classification & Operator Certification (§64413)
Point system based on source complexity, treatment processes, and population served determines facility grade (T1-T5, D1-D5). Shift operators must hold a certificate at or above the facility grade. Chief operator must also hold a certificate at or above the facility grade.
What to Watch on the Exam
- CA secondary standards are enforceable. That is the single biggest difference from federal and a near-guaranteed exam question.
- Perchlorate, hexavalent chromium, and 1,2,3-TCP are CA-only MCLs with no federal equivalent. The exam tests whether you know which contaminants are CA-specific.
- Nitrate MCL exceedance triggers Tier 1 public notification (24 hours) and requires a confirmation sample within 24 hours. That dual 24-hour requirement is testable.
- Barium is easy to overlook. Federal is 2.0 mg/L, California is 1.0 mg/L. An operator studying federal materials will have the wrong number.
- Consumer Confidence Reports (§64480-64483) apply only to community water systems, delivered annually by July 1, retained for 3 years.
Scope
Chapter 15 is the overarching CA drinking water quality chapter. It does not implement a single federal rule. It covers definitions, MCLs, monitoring, public notification, CCRs, and recordkeeping for all public water systems in California.