Condon Creek Proposed RNA Pond #1 



Climatic setting. The net annual precipitation balance for the 

 Condon Creek sites (from the MAPS database) is -8 inches, ranking 

 these sites toward the less evaporative end of the range shown by 

 sites of this classification. Mean monthly precipitation for the 

 Lindbergh Lake climatic station shows a relatively even 

 distribution with a January maximum. Annual precipitation totals 

 show the 3-year running average below the average for the period 

 of record throughout the 1980s. The running average recovered to 

 approximate the long-term average from 1990 to 1992. Data for 1993 

 were not recovered for this station. 



Geologic setting. The Condon Creek ponds are small glacial(?) 

 depressions in till of late Pleistocene age. The texture and 

 hydraulic characteristics of the till have not been described for 

 this area. Other glacial, fluvial and colluvial sediments may be 

 interbedded with till in the area. Any surficial sediments likely 

 include calcareous material derived from source areas underlain by 

 limestone and dolomite. 



The ponds occupy positions near the toe of the fault-bounded Swan 

 Range, which is underlain by argillitic and calcareous formations 

 of the Proterozoic Belt series. 



Hydrologic setting. The Condon Creek sites are glacial basins 

 lacking surface water outflow or discrete surface water inflow. 

 Dilute water chemistry suggests that water is supplied mainly by 

 precipitation and very local runoff. 



Basin characteristics. The Condon Creek ponds have very small 

 surface catchments and low catchment to wetland area ratios. 

 Depths of the ponds are unmeasured but probably shallow. 

 Topographic position suggests the possibility of ground-water 

 discharge to the ponds, but their dilute water chemistry is 

 probably inconsistent with volumetrically important ground-water 

 inflow. 



Water chemistry. Water chemistry in WET15 is very dilute, mildly 

 acidic and dominated by calcium and bicarbonate ions. Mineral 

 equilibria indicate substantial undersaturation with carbonate 

 species. Ammonium concentrations were high in this site, ranking 

 near the top for sites of this classification. Orthophosphorous 

 and total phosphorous concentrations ranked in the raid-range for 

 sample sites of this class. The total organic carbon concentration 

 was the highest for this class and among the highest for the entire 

 sample set. 



Arsenic and zinc were reported at their respective detection 

 limits; the iron concentration ranked in the mid-range for sites 

 in this class. Most other trace elements were below reporting 

 limits. 



