block-wall depressurization in Holland Township usually starts with a number somebody was not expecting.
What people describe first
- An older block wall with an open top course
- Radon entering high on the wall rather than at the floor
- A system that was installed under the slab and only got the reading part of the way down
Why this comes up in Holland Township
Holland sits almost wholly outside public supply. A well here draws from the rock along the Newark Basin–Musconetcong transition, which changes character across the township. That is part of the context any crew working in Holland Township has to design around.
Holland Township — the state's own numbers
43% of the 815 test results NJDEP holds for Holland Township were at or above the 4.0 pCi/L action level — 352 of them. That puts it in Tier 1 — high potential.
Farmsteads and river-road houses of 19th century date, with post-1970s single-family building on large lots inland.
What access looks like here
Large rural lots with room to work, though river-road properties can be tight against the road and the bank.
Construction permits go through Holland Township, and installing radon mitigation for a fee anywhere in New Jersey requires NJDEP certification.
The usual approach
Hollow block walls are a network of interconnected voids running from the footing to the top course, and soil gas uses them as a chimney. Treating them means sealing the top course and drawing suction from inside the cavity, usually alongside a sub-slab system rather than instead of one.
Typical cost in Hunterdon County, NJ
$1,800 – $3,200 — typical range, not a quote. What your building needs can only be settled by a certified business that measures it on site.
What it costs comes down to the foundation, the number of suction points, and where the pipe can run.
Who is allowed to do this in New Jersey
Under N.J.A.C. 7:28-27 this is not work a general contractor may take on. It requires a business certified by NJDEP for radon mitigation, with a certified mitigation specialist directing the work. We verify that on the state register, note the date, and route accordingly — but a verified certification is a fact, not a recommendation.
Not sure whether your number is a problem?
Write down what the system is doing and what the re-test said. We'll get it to crews who diagnose rather than guess.
Get quotes in Holland Township →Related
What tends to travel with this
Other work in Holland Township
Same ground, different question.
Block-wall depressurization nearby
Neighbouring towns on the same ground.