Petersburg Borough, AK: EPA's radon zone, explained

Petersburg Borough falls outside what EPA's 1993 radon zone map can rate directly, because its boundaries were redrawn after the map was made — the coverage gaps guide explains exactly which counties this affects and why.

Where Petersburg Borough sits nationally

Petersburg Borough, Alaska is home to about 3,436 people across 2,900.89 square miles. Population density there runs about 1 people per square mile.

What this actually means for a house in Petersburg Borough

Without a zone rating for Petersburg Borough to compare, the two national reference points still apply: EPA's action level is 4 pCi/L, against a national indoor average around 1.3 pCi/L and outdoor air near 0.4 pCi/L. EPA's guidance is unchanged by the absence of a zone rating here: test every home, since a zone (where one exists) only describes a county-wide average, never an individual house.

Next steps for a home in Petersburg Borough

For a Petersburg Borough homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Alaska's state radon program

For Petersburg Borough, an ongoing number beats a one-time test - a Airthings radon monitor tracks Petersburg Borough's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

Where Petersburg Borough's figures come from

The methodology guide shows exactly which EPA and Census sources feed Petersburg Borough's numbers. Petersburg Borough is one of a specific, documented set of counties EPA's map predates — the coverage gaps guide names every one.