Backflow testing in Michigan
1 utility list · 29 companies. Your utility decides which testers it accepts, so start from the utility that sent your notice.
Utility lists in Michigan
| Utility list | Area | Companies | Testers | vs national median | National rank (by companies) |
|---|---|---|---|---|---|
| Holland Board of Public Works | Holland | 29 | Company-level list | 0.5× | 28 of 33 |
Computed from the list of Holland Board of Public Works, as fetched 2026-11-04 (UTC). National median: 57 companies per list across the 33 utility lists we hold (n=33). National rank 1 = the list naming the most companies; equal counts share a rank. Testers: only lists that name each company's testers carry a count. Not in the company counts: 1 entry for an individual tester with no company named; we count those but do not republish them.
How current each list is
| Utility list | Version as printed | Date and age | Fetched (UTC) | We re-check it every |
|---|---|---|---|---|
| Holland Board of Public Works | “undated (PDF created 18 Feb 2026)” | 2026-02-18 (PDF file created date; the list prints no full date), 259 days before we fetched it; 14 of 22 by recency | 2026-11-04 | 365 days |
Computed from the list of Holland Board of Public Works, as fetched 2026-11-04 (UTC). Median age at fetch across the 22 lists we hold that carry a date: 206 days (n=22); rank 1 = the most recently dated list. A month-only or two-digit version (for example “7.2026”) is shown as printed and not turned into a date.
Where the listed companies are based
The Michigan list prints no town for the companies; this counts the area codes of their phone numbers instead: 29 of 29 companies show a phone here, with 3 area codes. The most common:
- Area code 616: 27 companies
- Area code 269: 1 company
- Area code 989: 1 company
Computed from the list of Holland Board of Public Works, as fetched 2026-11-04 (UTC). Area codes of the company phone numbers we publish; a company named on two lists counts once.
What kind of businesses are on the lists
The biggest difference from all the lists we hold: “plumbing” appears in 76% of company names on the Michigan list, against 25% across all of them.
| Company name contains | Companies (29) | Share | Share, all 2,590 companies we hold |
|---|---|---|---|
| Plumbing | 22 | 76% | 25% |
| Backflow or cross-connection | 0 | 0% | 24% |
| Fire | 1 | 3% | 17% |
| Irrigation, lawn, landscape or sprinkler | 0 | 0% | 10% |
| Mechanical, heating or air | 4 | 14% | 6% |
Computed from the list of Holland Board of Public Works, as fetched 2026-11-04 (UTC). A company named on two lists counts once. A name can match more than one row; 3 names here match none. The words say nothing about the quality of the work.
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