Community Assessment Report - Onsite Sewage Treatment ...

the type of structure existing on a parcel is the flow and strength of wastewater generated. Aseasonal residence can produce a different pattern of wastewater flow than a full-time residentialhome.Table 2: Parcel TypeUsage Pattern Number PercentageFull-time Residential 8 57%Seasonal Residential 6 43%2.3.3 SSTS TypeNo ISTS currently exist in the CAR area. The existing cluster SSTS is a drainfield locatedsouthwest of the served residences (Figure 4). Individual septic tanks served by a commoncollection line and lift station are present at each property.2.3.4 SSTS Likely Compliance StatusUpon visiting each individual parcel a determination was made regarding the potential that theindividual septic tanks and the cluster SSTS for the dwellings would be compliant or noncompliantwith Minnesota Rules Chapter 7080 and Chisago County ordinance. The clusterSSTS was considered non-compliant for two reasons:1. The system is ITPHS as identified from site reconnaissance. Effluent was noteddischarging from the surface of the drainfield in the northwest corner of the treatmentsite (Photo 1).2. The system fails to protect groundwater. Insufficient vertical separation exists betweenthe seasonally high groundwater and the bottom of the effluent dispersal area to allowadequate treatment of the wastewater via aerobic soil conditions before the effluententers into and mixes with the shallow groundwater at the site. In addition, the tanks thatare part of the system are not watertight; and therefore do not protect groundwater for thesame reason (insufficient vertical separation).T:\2797-01 Chisago County\CAR\ROLLINGS SHORES CAR 090712.docx2-4