Husband has very active hep c infection, inflamed liver, don't know anything else yet, could that be the cause of severe fluid retention in legs?

Yes...it can: Severe liver diseases as in cirrhosis, often due to hepc n/or alcohol etc..Can cause fluid retention in the abdomen (ascities) and swelling of legs. Often a difficult illness to manage, because the liver is so important an organ in term of its miriad of functions. He may have esophageal varices (enlarged veins in esophagus) which may bleed.. Regular visits with doc..Very important.. Good luck.

Possible: Liver failure, kidney failure, or heart failure all can result in fluid retention and swelling or edema of legs hepatitis c can also affect other organs other than liver, especially kidney and cause fluid retension.