Residential STP CAD Drawings

I need clear, well-structured civil CAD drawings for a small sewage treatment plant that will serve a residential area. The focus is on showing how everything fits together rather than producing highly detailed process diagrams.

Here is what I must see in the final package:
• Sewage pipe layout showing inlets, manholes, slopes and connections to the treatment units.
• Separate bottom, top and sectional layouts that make gradients, wall heights and slab levels unambiguous.

I will supply all key dimensions, invert levels and any local notes once we start, so you do not need to reference a particular code set—just follow the measurements I provide and keep the drawing layers clean and logically named. Please deliver editable AutoCAD (.dwg) files along with matching PDFs. A quick first draft and room for one round of adjustments would be ideal.