You have been asked to evaluate two different wells for safety. Well A and Well B have the same owner but are in different locations. Examine the results in the table for each of the wells.

| | Well A | | Well B |
|---------|---------------|-----------|---------------|
| Contaminant | Amount (mg/L) | Contaminant | Amount (mg/L) |
| Arsenic | 0.040 | Arsenic | 0.06 |
| Cadmium | 0.007 | Barium | 3.0 |
| Cyanide | 0.31 | Cadmium | 0.001 |
| Nitrate | 12 | Lead | 0.000 |
| Thallium | 0.000 | Nitrate | 0.00 |

Refer to the data table and determine which contaminants are found in toxic quantities in Wells A and B.

Let's carefully evaluate the given contaminants for each well to determine which ones are found in toxic quantities.

First, we need to know the toxic thresholds for each contaminant:
- Arsenic: 0.01 mg/L
- Cadmium: 0.005 mg/L
- Cyanide: 0.2 mg/L
- Nitrate: 10 mg/L
- Thallium: 0.002 mg/L
- Barium: 2 mg/L
- Lead: 0.01 mg/L

Now, let's look at the contaminant levels in Well A:
1. Arsenic in Well A: 0.040 mg/L
- Threshold: 0.01 mg/L
- Since 0.040 is greater than 0.01, arsenic is found in toxic quantities.

2. Cadmium in Well A: 0.007 mg/L
- Threshold: 0.005 mg/L
- Since 0.007 is greater than 0.005, cadmium is found in toxic quantities.

3. Cyanide in Well A: 0.31 mg/L
- Threshold: 0.2 mg/L
- Since 0.31 is greater than 0.2, cyanide is found in toxic quantities.

4. Nitrate in Well A: 12 mg/L
- Threshold: 10 mg/L
- Since 12 is greater than 10, nitrate is found in toxic quantities.

5. Thallium in Well A: 0.000 mg/L
- Threshold: 0.002 mg/L
- Since 0.000 is not greater than 0.002, thallium is not found in toxic quantities.

Now, let's look at the contaminant levels in Well B:
1. Arsenic in Well B: 0.06 mg/L
- Threshold: 0.01 mg/L
- Since 0.06 is greater than 0.01, arsenic is found in toxic quantities.

2. Barium in Well B: 3.0 mg/L
- Threshold: 2 mg/L
- Since 3.0 is greater than 2, barium is found in toxic quantities.

3. Cadmium in Well B: 0.001 mg/L
- Threshold: 0.005 mg/L
- Since 0.001 is not greater than 0.005, cadmium is not found in toxic quantities.

4. Lead in Well B: 0.000 mg/L
- Threshold: 0.01 mg/L
- Since 0.000 is not greater than 0.01, lead is not found in toxic quantities.

5. Nitrate in Well B: 0.00 mg/L
- Threshold: 10 mg/L
- Since 0.00 is not greater than 10, nitrate is not found in toxic quantities.

Based on this evaluation, the contaminants found in toxic quantities for each well are:

- Well A:
- Arsenic
- Cadmium
- Cyanide
- Nitrate

- Well B:
- Arsenic
- Barium