Chloride level depends on the fish type - obviously your talking about freshwater since brackish or marine would not be an issue. Different rivers have different natural levels. Google the fish type and chloride and you'll know - but general rule of thumb - no more then 50-75ppm. Algae - some algae can thrive at 0 mg/l nitrogen - phospherous at even 0.01mg/l can feed algae bloom (blue/green) - you've got more then enough to keep algae bloom going. Yellow/green are almost totally photosynthetic and can bloom at nitrogen levels below 0.02mg/l.

The above post have pointed you in the right direction; but I assume there is more to your question.

1. Are you looking at ridding a pond of algae without causing a fish kill?

2. Are you being accused for a fish kill?

Please do elaborate as I'm sure we can give assistance.

I worked for the Louisiana Department of Environmental Quality for a number of years and investigated numerous fish kills and none of them were related to high chlorine content.  

I've seen where UV systems go down so a facility overdoses with the chlorine causing the pH on their outfall to be out of range with no off-site consequences noted.