BackflowNear Test-Due Reminder

Approved backflow testers in Baltimore, MD

53 backflow testing businesses work within 25 miles of Baltimore, 4 of them based in town. 10 have testers on Maryland's roster and 43 are on the approved tester list of 4 water utilities.

53 businesses within 25 miles

Backflow testing companies near Baltimore

What the badges mean
✓ MD Certified Backflow Tester Verified
A state roster lists at least one certified tester at this business, with a current certificate. The state sets the exam and renewal.
✓ MD Utility-Approved Tester Verified On the city list
The company is on a water utility's own approved list (the second badge names the list). That is the utility's approval, not a state license, and it counts for that utility.
3 certified testers
How many certified testers the roster lists at this business.
★ 4.8 (25 reviews)
The Google rating, shown as Google reports it. It does not change the order.

Order is by our quality score, never by payment. How we verify listings.

Are you a backflow testing company near Baltimore? One sponsor per county, clearly labelled. Sponsor this county

Fireline Corporation

90/100
✓ MD Utility-Approved Tester Verified ★ 3.5 (51 reviews) On Anne Arundel County list Backflow Testing

4506 Hollins Ferry Rd, Baltimore, MD 21227 · 2 mi from Baltimore

Call (410) 247-1422 Details Website
Verified Oct 2026 · Unclaimed listing

Mahon Plumbing Inc.

90/100
✓ MD Utility-Approved Tester Verified ★ 4.9 (284 reviews) On City of Rockville list Backflow Testing

6824 Fort Smallwood Rd Ste. A, Baltimore, MD 21226 · 5 mi from Baltimore

Call (410) 766-8566 Details Website
Verified Oct 2026 · Unclaimed listing

Slo-Flo Plumbing

90/100
✓ MD Utility-Approved Tester Verified ★ 5 (256 reviews) On Anne Arundel County list Backflow Testing

792 Jennie Dr, Severn, MD 21144 · 7 mi from Baltimore

Call (443) 734-8609 Details Website
Verified Oct 2026 · Unclaimed listing

JA Smith & Company

90/100
✓ MD Utility-Approved Tester Verified ★ 4.9 (34 reviews) On Anne Arundel County list Backflow Testing

7080 Kit Kat Rd, Elkridge, MD 21075 · 9 mi from Baltimore

Call (410) 796-7532 Details Website
Verified Oct 2026 · Unclaimed listing

Carson Plumbing

90/100
✓ MD Utility-Approved Tester Verified ★ 5 (181 reviews) On Anne Arundel County list Backflow Testing

1420 Washington Ave, Severn, MD 21144 · 9 mi from Baltimore

Call (410) 963-0204 Details Website
Verified Oct 2026 · Unclaimed listing

Anne Arundel Plumbing

90/100
✓ MD Utility-Approved Tester Verified ★ 4.5 (75 reviews) On Anne Arundel County list Backflow Testing

7930 Wooded Glen Ct, Pasadena, MD 21122 · 9 mi from Baltimore

Call (410) 437-0300 Details Website
Verified Oct 2026 · Unclaimed listing

Russell R. Dwyer, Inc.

90/100
✓ MD Certified Backflow Tester Verified ★ 4.8 (21 reviews) On WSSC Water listOn Anne Arundel County list Backflow Testing

8377 B Jumpers Hole Rd, Millersville, MD 21108 · 9 mi from Baltimore

Call (410) 647-3030 Details Website
Verified Oct 2026 · Unclaimed listing

Heil Plumbing

90/100
✓ MD Utility-Approved Tester Verified ★ 4.9 (2709 reviews) On Anne Arundel County listOn City of Rockville list Backflow Testing

8177 Mission Rd, Jessup, MD 20794 · 10 mi from Baltimore

Call (410) 799-7727 Details Website
Verified Oct 2026 · Unclaimed listing

1st Choice Plumbing

90/100
✓ MD Utility-Approved Tester Verified ★ 4.9 (147 reviews) On Anne Arundel County list Backflow Testing

4471 Mountain Rd, Pasadena, MD 21122 · 11 mi from Baltimore

Call (443) 790-9571 Details Website
Verified Oct 2026 · Unclaimed listing

B&C Plumbing

90/100
✓ MD Utility-Approved Tester Verified ★ 4.6 (15 reviews) On Anne Arundel County list Backflow Testing

516 Pine Tree Dr, Severna Park, MD 21146 · 12 mi from Baltimore

Call (410) 647-1106 Details Website
Verified Oct 2026 · Unclaimed listing

Lloyd Plumbing Corporation

90/100
✓ MD Utility-Approved Tester Verified ★ 4.3 (6 reviews) On Anne Arundel County listOn City of Rockville list Backflow Testing

9691 Gerwig Ln # I, Columbia, MD 21046 · 12 mi from Baltimore

Call (410) 203-2720 Details Website
Verified Oct 2026 · Unclaimed listing

Price reports

What a backflow test costs in Baltimore

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Published prices nationwide

$29.99 to $100 per assembly

Based on 14 published prices · Read Oct 2026 Prices testing businesses list on their own websites, from our cost guide. Listed prices, not what people paid.

Every published price, with its source: what a backflow test costs.

Failed test? Published repair, rebuild and replacement prices: what a backflow repair or replacement costs.

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Baltimore City Department of Public Works: backflow test rules

  • Who must test. In high-hazard buildings, each floor with hazardous water uses needs a backflow device on the line supplying that floor, in addition to the one on the main. Source.
  • How the report is filed. Under section 607.3.1.3, all testing and inspections must be recorded on a certificate attached to the backflow prevention device. Source.
  • Tester registration. Under the Baltimore plumbing code (section 608.1.1), only a person licensed by the State as a master or journeyman plumber may connect backflow prevention devices to the city water supply. Source.
  • If a test is missed. A cross-connection that does not comply with the law is grounds for immediate termination of water service; people given notice must act immediately to control it. Source.

Everything about Baltimore City Department of Public Works's backflow program

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Backflow testing questions in Baltimore

Where are the backflow testing businesses listed for Baltimore based?

53 backflow testing businesses are listed within 25 miles of Baltimore. 4 are based in Baltimore itself, 25 more within 15 miles and 24 further out, up to 25 miles away. Other towns with more than one listing: Columbia (5), Annapolis (4) and Beltsville (4). The closest is Fireline Corporation, 2 miles from Baltimore.

Which tester lists are the businesses near Baltimore on?

10 have testers on Maryland's roster and 43 are on the approved tester list of 4 water utilities.

Which water utility sets the backflow test rules in Baltimore?

Baltimore City Department of Public Works. Who must test: In high-hazard buildings, each floor with hazardous water uses needs a backflow device on the line supplying that floor, in addition to the one on the main.

How many of the backflow testing businesses near Baltimore have Google reviews?

50 of the 53 listed for Baltimore have 3 or more Google reviews. Heil Plumbing has the most reviews, 2,709, with an average of 4.9 stars, as Google showed them at our last check.

Approved list: WSSC Water plumbing firms providing cross-connection related services, WSSC Water.

Approved list: Backflow Prevention Assembly Service Providers, DC Water.

Approved list: Anne Arundel County accepted plumbing companies providing backflow related services, Anne Arundel County Department of Public Works.

Approved list: City of Rockville certified backflow prevention testers, City of Rockville Department of Public Works.

Related site: Testing a fire line? The sprinkler system behind it needs its own inspections by a state-licensed fire protection company. Licensed fire sprinkler inspectors near Baltimore on FireInspectorNear, our sister directory.

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