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City water management is analyzing water samples from the local river for water pollutants that could be toxic to humans if found in drinking water. Their collection data is below.


Samples

Location

Nitrates

Carbamates

1

Two miles downriver from drinking water uptake facility

12 mg/L

0.06 mg/L

2

One mile downriver from drinking water uptake facility

9 mg/L

2 mg/L

3

One mile upriver from drinking water uptake facility

8 mg/L

0.04 mg/L

4

Two miles upriver from drinking water uptake facility

10 mg/L

0.05 mg/L

Toxic levels reached when nitrates are greater or equal to 10 mg/L and/or carbamates are greater or equal to 0.04 mg/L.

Which sample location(s)have nitrates or carbamates at toxic levels that could be collected by the water uptake facility?
Samples 1, 2, 4
Samples 1 and 4
Samples 3 and 4
Only sample 4

Respuesta :

marianaegarciaperedo

Aquatic toxicity is found in the four sample sites. But since the water uptake facility collects water from upriver, the correct option is C. Samples 3 and 4.

What is aquatic toxicity?

Aquatic toxicity is the property of a substance to causes harmful effects on aquatic or water-dependent organisms.

Aquatic toxicity can be either,

  • Sharp ⇒ nocive effects after a short exposition period
  • Cronic ⇒ nocive effects after a long exposition period

Aquatic toxicity depends on the substance type and its concentration in water.

--

According to the problem statement, toxic levels are reached when

  • nitrates are greater or equal to 10 mg/L

and/or

  • carbamates are greater or equal to 0.04 mg/L.

Sample 1 ⇒ Two miles downriver from drinking water uptake facility

  • Nitrate → 12 mg/L ⇒ > 10 mg/L ⇒ toxic
  • Carbamate → 0.06 mg/L ⇒ > 0.04 mg/L ⇒ toxic

Sample 2 ⇒ One mile downriver from drinking water uptake facility

  • Nitrate → 9 mg/L ⇒ < 10 mg/L ⇒ not toxic
  • Carbamate → 2 mg/L  ⇒ > 0.04 mg/L ⇒ toxic

Sample 3 ⇒ One mile upriver from drinking water uptake facility

  • Nitrate → 8 mg/L ⇒ < 10 mg/L ⇒ not toxic
  • Carbamate → 0.04 mg/L ⇒ = 0.04 mg/L ⇒ toxic

Sample 4 ⇒ Two miles upriver from drinking water uptake facility

  • Nitrate → 10 mg/L ⇒ = 10 mg/L ⇒ toxic
  • Carbamate → 0.05 mg/L ⇒ > 0.04 mg/L ⇒ toxic

The four sample sites have toxic levels. Both of the substances concentrations or at least one of them reaches the toxic level at each site.  

However, since water uptake facility can colect water from upriver, we only need to consider these sample sites.

The correct option is C. Samples 3 and 4.

You can learn more about aquatic toxic substances at

https://brainly.com/question/13721156

#SPJ1  

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