We have the same problem here ...
Published by Danny Liufalani, DIRECTOR -Asia Pacific/Australia/New Zealand at Viroment Enerco US
We have the same problem here for so many years...things a improving slowly but very expensive...I would recommend to look at the latest technology,affordable and do away with holding ponds or oxidising..This is a real time treatment system to do away with odour ...should you need more information I will be happy to help....danny@viroment.com