Hi Marietta! One of the first thing you should do is to gather all information possible about your building site, and new structure, and then make an appointment with your local Sanitarian or Health Director. He or she should be able to share with you what types of wastewater disposal systems are acceptable within their jurisdiction. It is my guess that lagoons would not be acceptable by the health regulations and should be discouraged for several reasons. These open impoundments could harbor pathogenic bacteria which then can spread into other ecosystems by higher animal populations. A septic tank and a properly designed infiltration or treatment system should keep all pathogens beneath the surface to minimize the spreading of disease and provide an acceptable level of treatment before the effluent reaches the groundwater. For one option to treat your wastewater you may go to http://nitrap.com/formwc2.html . Other option are leaching trenches and gallery type structures. The conventional stone/gravel trenches would be preferred over chamber systems since these provide important pre-treatment and also have significant surface area on the sidewalls for extended operational life.