Underground Storage Tank Ordinance No. 4332
Attachment "D"

Sampling Protocol

The following information regarding sampling activities contains general guidelines. All sampling activities are subject to conditions identified during field activities.

WATER NOT PRESENT IN TANK EXCAVATION

  1. Samples shall be taken one to two feet below the excavation at the worst-case locations.  
  2. If areas of obvious contamination are observed, including any excavated material, they must be sampled and analyzed.
Water not present in tank excavation
Tank Size Minimum Number of Soil Samples Location of Soil Samples
Less that 1,000 gallons  One per tank     Fill or pump end of tank
1,000 to 10,000 gallons    Two per tank One at each end of tank
Greater than 10,000 gallons    Three per tank     Ends and middle of tank   
Piping One Every 20 lineal feet

WATER PRESENT IN THE TANK EXCAVATION

  1. The tank pit may be purged and allowed to refill before sampling. The purged water is to be disposed of properly at an approved facility.
  2. The water sample is to be representative of water in the tank excavation.
  3. If areas of obvious contamination are observed, including any excavated material, they must be sampled and analyzed.

 

Water present in the tank excavation
Tank Size Minumum number of Soil Samples Location of Soil Samples Minimum Number of Water Samples
10 ,000 gallons or less   Two Ends of tank One
Greater than 10,000 gallons    
tank cluster 
Four Ends of tank One