NRES 251 - Water Exam II

Q = dh/dl x K x A

The equation for groundwater discharge.

What is dh/dl?

hydraulic gradient (change in the elevation in the water table divided by the distance between the two points).

How do you get to dh/dl?

Subtract Top of Casing (TOC) from depth to groundwater to get hydraulic head, and from there you can find dh/dl.

What is K?

hydraulic conductivity (measured in ft per day).

What causes acid rain?

NO_x and SO_x.

Alkalinity

the ability of a water body to resist acidification. It comes from limestone in parent material.

Most waterbodies have a pH of…?

6-8.

What did the Romans use for pesticides?

Burning brimstone (sulfur) and heavy metals.

What was used circa 1900 to kill insects in apple orchards?

Lead arsenate.

What pesticide made the shells of bald eagle eggs dangerously thin and fragile?

DDT.

What intense chemical calls deformation and reproductive issues in amphibians after leaching into waterways?

Atrazine.

What affect did Roundup have on the surrounding organisms?

Research is now indicating that glyphosate impacts hormones in amphibians and embryo development in vertebrates. Weeds are now showing resistance to glyphosate.

What will using the same pesticides every year do to the local pests?

They will develop immunities.

Hydrocarbons

any compound that contains only C and H atoms.

Why is crude oil such an issue?

It is a combination of various hydrocarbons (75% aliphatic - nontoxic; 15% aromatic - toxic; 10% other).

What’s the deal with aromatic carbons?

These structures are in a ring form, each point representing a carbon. Because of this structure and that every carbon is double bound to itself, they are persistent. They don’t break down as readily and are very toxic to organisms.

Compare small amounts of oil to large oil spills.

Small amounts of oil are just as bad as the big oil spills, which also indicates our need to revise the stormwater drains we have. 

PCBs

Polychlorinated Biphenyls. They are used in electrical/industrial equipment, paints, plastics, and dyes in carbonless paper. They are very stable and persistent, and that’s why they were used. There are 209 different congeners (depending on where the Cl is located on benzene rings). 

PCBs have a half life of…?

23 years.