Alternative systems proposed may include, but shall not be limited to, any of the following:

1. (1) humus or other composting toilets;
2. (2) alternative mounded systems (such as the "Wisconsin mound") designed to overcome limiting site conditions;
3. (3) any system designed to chemically or mechanically aerate, filter, separate or pump the liquid, semi-solid or solid constituents in the system; or
4. (4) any system designed specifically to reduce, convert, or remove nitrogenous compounds, phosphorus, or pathogenic organisms (including bacteria and viruses) by biological, chemical, or physical means.