Question

the epa has guidelines regarding the concentrations of different metals that are safe to have in drinking water. these are referred to as action levels. take a look at this table of epa action levels to find out if the lead concentration you calculated from aliyas house is cause for concern.
note that although no amount of lead is actually safe in drinking water, if the concentration of a substance reaches or exceeds the action level, the city has to take additional actions to control the corrosion.
does your calculated level of lead meet the action level?
yes, the value exceeds the action level
yes, the value matches the action level
no, the value is below the action level
no, the value is indicative of the water supplys safety
i cant tell, given that the units are not in molarity
these guidelines should help you with your task. i got them from the epas (environmental protection agency) website.
your concentration of lead value:
0.000000105 m
epa action levels
lead: 15 ppb
arsenic: 10 ppb
copper: 1300 ppb

Explanation:

Step1: Convert molarity to ppb

The molar mass of lead (\(Pb\)) is \(M = 207.2\space g/mol\).
The formula to convert molarity (\(M\)) to \(ppb\) (parts - per - billion) is \(ppb=\frac{\text{molarity}(mol/L)\times\text{molar mass}(g/mol)\times10^{9}}{1000}\) (since \(1\space L\) of water has a mass of approximately \(1000\space g\)).
Given \([Pb]=0.000000105\space M\)
Substitute the values into the formula:

$$
LATEXBLOCK0
$$

Step2: Compare with EPA action level

The EPA action level for lead is \(15\space ppb\).
Since \(21.756\space ppb>15\space ppb\)

Answer:

Yes, the value exceeds the action level