Borough, York County

Radon Mitigation in Delta, PA

Updated September 30, 2026

Delta is a borough in York County with about 807 residents and 372 homes, median year built 1938. It is surrounded on three sides by Peach Bottom Township. Peach Bottom slate quarried near Delta was judged the finest in the world at the 1850 Crystal Palace Exposition. 57.4% of PA DEP radon tests in its ZIP codes came back at or above the action level, above the county's 52.5%.

What the PA DEP test records show for Delta

ZIP 17314 covers essentially all of Delta, so these numbers are about as local as public radon data gets.

Half of the story is the median. The other half is the tail: 31.8% of tests here were 10 pCi/L or higher and 18.7% were 20 or higher. The top reading on record in these ZIP codes is 522 pCi/L. Neighboring houses can differ by a factor of ten, so none of this tells you what your house is. It tells you the odds are high enough that a $15 to $30 test kit is worth buying.

Tests people chose to run, not a random survey. Details on the York County radon levels page.

Basement readings versus first-floor readings

In ZIP 17314, basement tests have a median of 5.6 pCi/L, while tests taken on the first floor have a median of 4 pCi/L (79 first-floor tests). The gap is smaller than in most of the county, which means readings upstairs here are not much of a relief from the basement number.

It also explains why two neighbors can get very different results. One tested a finished basement, the other tested a first-floor bedroom. For a decision about mitigation, the test that counts is the one from the lowest level anyone spends time in.

Radon results by decade in ZIP 17314

The share peaked in the 2000s at 66% and sits at 45.3% for tests since 2020. A drop that size is mostly about who is testing, not the ground. More recent tests come from home sales and from retests after a system went in, and both pull the share down. The rock under Delta has not changed. 179 tests have been logged in 17314 since 2020, so people here are still testing.

Housing in Delta and what it means for a system

Census Bureau, American Community Survey 2020 to 2024:

65.1% of the homes in Delta were built before 1940, against 18.3% county-wide. Houses that old usually sit on stone or early block foundations with no vapor barrier and plenty of joints, which gives soil gas more ways in. They are still very fixable. The installer just spends more time sealing, and sometimes needs a second suction point, which is why these jobs tend to land toward the upper end of the cost range.

Only about 56.2% of homes in Delta are owner-occupied, so a lot of people here rent. Pennsylvania does not require landlords to test, but a tenant can ask, and a landlord can test between tenancies without much hassle. Our landlord testing guide covers the details.

Cost-wise, expect older houses in Delta to land in the $1,200 to $2,500 part of the range once sealing and a possible second suction point are counted. Newer houses are usually the standard $800 to $1,500 job. Full ranges on the cost page.

Where we work in Delta

Public schools here are part of South Eastern School District. Peach Bottom slate quarried near Delta was judged the finest in the world at the 1850 Crystal Palace Exposition.

Installers must hold a PA DEP radon mitigation certification (how to check), and permit questions go to the borough office at www.deltaborough.us.

Common questions

Is radon a problem in Delta?

Yes. PA DEP has 972 tests on record from the ZIP code covering Delta, and 57.4% of them came back at or above the EPA's 4.0 pCi/L action level. 18.7% were at 20 pCi/L or more. The county-wide rate is 52.5%.

What is the average radon level in ZIP 17314?

The median of 972 PA DEP tests in ZIP 17314 is 5.1 pCi/L and the mean is 15.8 pCi/L. A mean that far above the median means a long tail of very high readings, topping out at 522 pCi/L.

Nearby

Peach Bottom Township 57.4%, Lower Chanceford Township 60.5%. Share of PA DEP tests at or above 4.0 pCi/L, against 57.4% here.