Nederland Fire has a split ISO classification:

Within Town Limits, due to fire hydrants the ISO CLASS is 6.

Outside of Town due to limited water supply the ISO CLASS is 9.

The District is actively working on installing community cisterns, a station expansion on Ridge Rd to house a new water tender and many other activities to lower your ISO rating. We expect to be re-evaluated in late 2009.

ISO's Public Protection Classification (PPCTM) Program

To help establish appropriate fire insurance premiums for residential and commercial properties, insurance companies need reliable, up-to-date information about a community's fire-protection services. ISO provides that information through the Public Protection Classification (PPCTM) program.

What is the PPC program?
ISO collects information on municipal fire-protection efforts in communities throughout the United States. In each of those communities, ISO analyzes the relevant data using our Fire Suppression Rating Schedule (FSRS). We then assign a Public Protection Classification from 1 to 10. Class 1 generally represents superior property fire protection, and Class 10 indicates that the area's fire-suppression program doesn't meet ISO's minimum criteria.

By classifying communities' ability to suppress fires, ISO helps the communities evaluate their public fire-protection services. The program provides an objective, countrywide standard that helps fire departments in planning and budgeting for facilities, equipment, and training. And by securing lower fire insurance premiums for communities with better public protection, the PPC program provides incentives and rewards for communities that choose to improve their firefighting services.

http://www.isomitigation.com/ppc/0000/ppc0001.html for more information