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Best Radon Testing in Santa Ana, CA

Compare 15 local radon testing providers in Santa Ana. Verified listings with real contact info.

15 verified providers · Updated 2026-04-16

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1

JLM Environmental

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2

A-Tech Consulting, Inc.

4.8 ★ (38 reviews)

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3

IHS Environmental Inc

5.0 ★ (12 reviews)

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1

JLM Environmental

12913 Harbor Blvd Ste Q-3 305, Garden Grove, CA 92840
Mon–Fri 8am–5pm · Sat 8am–4pm · Sun Closed
2

A-Tech Consulting, Inc.

4.8 (38 reviews)
1640 N Batavia St, Orange, CA 92867
Mon–Fri 7:30am–5:30pm · Sat–Sun Closed
3

IHS Environmental Inc

5.0 (12 reviews)
1601 Dove St #276, Newport Beach, CA 92660
Mon–Fri 24hrs · Sat–Sun Closed
4

Signature Home Inspection

4.9 (415 reviews)
74 Navarre, Irvine, CA 92612
Open 24 Hours
5

Affordable Home Inspection Inc.

4.1 (23 reviews)
16787 Beach Blvd #342, Huntington Beach, CA 92647
Mon–Sat 8am–6pm · Sun Closed
6

Omega Environmental Services, Inc.

5.0 (2 reviews)
1133 Camelback St #7261, Newport Beach, CA 92658
Mon–Fri 8am–5pm · Sat–Sun Closed
7

Clark Seif Clark, Inc. (CSC)

5.0 (4 reviews)
4010 Watson Plaza Dr Suite 170, Lakewood, CA 90712
Open 24 Hours
8

Elite Group Inspection Professionals

4.8 (2,282 reviews)
21700 Copley Dr #390, Diamond Bar, CA 91765
Mon–Fri 5am–7pm · Sat 6am–5pm · Sun 8am–2pm
9

Quest Property Inspections

5.0 (37 reviews)
3390 Garretson Ave, Corona, CA 92881
Mon–Sat 8am–5pm · Sun Closed
10

Coastal Property Inspections

5.0 (20 reviews)
30251 Golden Lantern STE-E # 361, Laguna Niguel, CA 92677
Mon–Sat 8am–6pm · Sun 9am–5pm
11

The Phase One Group

5.0 (18 reviews)
324 S Diamond Bar Blvd UNIT 130, Diamond Bar, CA 91765
Mon–Fri 8am–5pm · Sat–Sun Closed
12

Elite Group Inspection Professionals

5.0 (1,515 reviews)
9480 Utica Ave #608, Rancho Cucamonga, CA 91730
Mon–Wed 8am–7pm · Thu–Sat 8am–5pm · Sun 8am–2pm
13

Diamond Property Inspections

5.0 (117 reviews)
16721 Multiview Dr, Lake Mathews, CA 92570
Mon–Sun 8am–10pm
14

Pillar To Post Home Inspectors - Mike Booth

5.0 (151 reviews)
9854 Cerise St, Rancho Cucamonga, CA 91730
Mon–Sat 8am–6pm · Sun Closed
15

Radon Mitigation Corp. of America

6207 Lochvale Dr, Rancho Palos Verdes, CA 90275

Frequently Asked Questions

How much does radon testing cost in California?

Professional radon testing typically costs $175 to $350. Short-term tests (48-96 hours) are used for real estate transactions. Long-term tests (90+ days) provide the most accurate annual average. **CDPH** recommends professional testing over DIY kits for real estate transactions, though DIY kits ($20-$40) are available at hardware stores.

Why is radon especially concerning in California?

California has varying radon levels depending on geology. **Granitic foothill counties and other radon-prone geologic zones** have elevated radon risk due to bedrock composition. Even other areas of the state have measurable radon. **CDPH** considers it a public health issue and publishes county-level radon data.

Are radon testers required to be certified in California?

California does not maintain a single statewide radon tester license like some trades. **CDPH** and professional organizations like the National Radon Proficiency Program (NRPP) or National Radon Safety Board (NRSB) recommend certified testers. For real estate transactions, use a certified professional to ensure legally defensible results.

What happens if my California home has high radon levels?

If radon levels exceed 4 pCi/L, the EPA and **CDPH** recommend installing a radon mitigation system. Sub-slab depressurization is the most effective method and typically costs $1,000 to $2,000. NRPP- or NRSB-certified mitigation contractors can perform installation. Mitigation reduces levels by up to 99%.

When should I test for radon in my California home?

**CDPH** recommends testing all homes, especially in high-risk areas. Test when buying or selling, after major renovations affecting the foundation, or if you have never tested. Testing during cooler months (November through March) with windows closed provides the most representative results. Re-test every 2 years or after major changes to the home.

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