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Engin}ering

P.O. Box 519, 210 E MainMT. VERNON. OR 97865

PHONE (541)932-4520FAX (541)932-1430EUAlL djst2@ortelconet

LEHMAN HOT SPRINGSSEWER LAGOON LEAK STUDY

Need:This study is performed at the request of Patrick Lucas, President of LehmanDevelopment Corporation.

Purpose:The purpose of this study is to determine if there is significant leakage from ether theexisting primary or secondary wastewater treatment lagoons. For the purposes of thisstudy, the primary lagoon will be referred to as the "upper pond", and the secondarylagoon will be referred to as the "lower pond".

Conditions:• The test period is conducted from mid-day on May 27, through mid-day on June

3, 2009, or a period of 6 full days.

• There is no measurable precipitation through the test period.

• Temperature is near or approximately normal, with high temperatures in the 70s'and lows in the 40s'

• Wind and Humidity are approximately normal for this time of year with noextremes.

• There is no inflow to the lagoon system during the test period.

• Each Lagoon (Pond) is hydraulically isolated.

Methodology:

Leakage is determined as based monitoring the water surface levels in each pond.Evaporation and precipitation are determined by floating standard, circular 47.5"xlO"evaporation pans in each pond. As stated previously, there was no precipitation duringthe test period, therefore only evaporation was accounted for.

Evaporation is determined by measuring the water level of the pan at the beginning of thetest period then again at the end. Evaporation conditions are maintained as near to thosein each pond by actually floating the evaporation pans in the pond on which evaporationis to be determined, (Temperature, wind, and humidity). In order to account for normalpan evaporation being normally less than pond evaporation, a factor of 0.75 is applied tothe pan measurements.

Leakage is then determined by comparing the pond water surface difference with the panwater surface difference. Pond surface difference more than pan surface difference isleakage. It should be noted that "Oregon Department of Environmental Quality"Guidelines for estimating leakage from existing sewage lagoons, considers 1/8" per dayor less to be normal.

Raw Data as Measured in the Field

UPPER POND LOWER PONDBegin Test May 27,2009 @ 12:30 P.M.

Evaporation Pan Depth = 0.39' Evaporation Pan Depth = 0.35'Water Surface Elevation = 98.76' Water Surface Elevation = 91.62'

Change in Pan Surface = 0.08'Change in Pond Surface = 0.06'

Change in Pan Surface = 0.08'Change in Pond Surface = 0.06'

End Test June 3, 2009, @ 11:30 A.M.Evaporation Pan Depth = 0.31' Evaporation Pan Depth = 0.27'Water Surface Elevation = 98.70' Water Surface Elevation = 91.56'

Leakage:

Upper Pond Leakage = 0.06' - 0.75(0.08') = 0Lower Pond Leakage = 0.06'- 0.75(0.08') = 0

Over a 6 day period this is a pond drop of 1/8" per day and an identical pan drop of 1/8"per day in each pond.

It should be pointed out that, a compilation of "Oregon Evaporation Station Averages"taken in Ukiah (15 miles to the west) provide the following:

Average Evaporation in May @ 3.83" and Average Evaporation in June @ 4.38"

This provides an average monthly evaporation for the study period of 3.83", or 1/8" perday as determined above.

Conclusion:

Within the scope and precision of this study or the "Oregon Department ofEnvironmental Quality" Guidelines for estimating leakage from existing sewagelagoons". There is No Significant Leakage From Ether Pond.

BY:Douglas M. Ferguson, P.E., P.L.S.PresidentFerguson Surveying & Engineering

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