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
- Samples shall be taken one to two feet below the excavation at the worst-case locations.
- 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
- 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.
- The water sample is to be representative of water in the tank excavation.
- 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 |
Minimum 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 |