Sodium Dichromate (Chromium) and various effects on the environment?

I have searched the web, including HSDB, and EPA.. but am having difficulty finding some question regarding Sodium dichromate (Chromium (VI)) on cattle, fish, humans, and the enviro.  

The questions I have are:

1.) Finding the methods of calculating or assessing the effects of Sodium dichromate

2.) Is there also an analytical methods for measuring the effects in these areas.

3.) What the "mechanism of action" would be for Chromium.

4.) And the parameters used for toxicity in the above areas… fish, cattle, human and the enviro.

I would greatly appreciate any help you could offer in helping me.

Extra info that might help Scenario.
An environmental accident has occurred where 120 km of asphalt-paved road has been coated with sodium dichromate.  

1. Along the side of this 120 km stretch of road is local general store service station.
  
2. If it rains the water will move the sodium dichromate into the roadside ditches, into dugouts and a small creek flowing with spring runoff.  

3. The roadway ditches inter-connect with the dugouts used for both domestic and livestock water.  

4. Some of the dugouts have been stocked with rainbow trout.  

5. One dugout was treated last summer with copper sulfate for control of aquatic plants, currently are now covered with ice.