Journal of Cold Regions Engineering

Effective (design) thermal resistivity values for use of rigid, cellular polystyrene foam insulation in below-ground frost-protection applications play an important role in the success of the ASCE 32-01 standard. The ASCE 32-01 standard is currently recognized in U.S. model building codes as a cost-effective means of protecting building foundations against frost heave in regions with seasonal ground freezing and no permafrost. The long-term thermal performance of foundation insulation used for this purpose is, therefore, a critical building performance concern. This same concern also has relevance to sustained performance of below-ground insulation used for energy conservation purposes. This paper provides a critical review and analysis of data reported in the literature on below-ground thermal performance of rigid, cellular polystyrene foam insulations. These products can be molded expanded polystyrene or extruded polystyrene as defined by ASTM C578 in ASTM 2008 Standard. The findings serve to document and confirm effective thermal resistivity values originally incorporated into the ASCE 32-01 standard for frost protection of building foundations.

Fecal coliform (FC) analyses were conducted on weekly water samples collected from a single watershed over a 2-year period in Anchorage, Alaska. Although peak FC concentrations $\left(>100\text{FC}/100\text{mL}\right)$ were observed primarily during the warmer months, lower FC levels $\left(>20\text{FC}/100\text{mL}\right)$ could be observed throughout the year in the urbanized portion of the watershed. Median annual FC counts ranged from 3 FC/100 mL at an undeveloped site to 49 FC/100 mL at one of the urbanized sites. Median FC concentrations were found to be significantly higher in the summer compared to the winter at two locations directly downstream from a lake ( $p=0.011$ and 0.029), but not at the sites upstream or distant from the lake. FC-discharge relationships indicated a significant negative correlation between FC concentration and discharge at two sites ( $p=0.030$ and 0.035) and no significant correlation at the remaining three sites. In total, the results indicated that the water quality was impacted not only by peakwarm season loading events, but also by chronic low-level loading throughout the year.