Pro Plumbers

Bacteria have been shown to live in "premises plumbing systems". The latter refers to the "pipes and fixtures within a building that transport water to taps after it is delivered by the utility".[34] Community water systems have been known for centuries to spread waterborne diseases like typhoid and cholera, however "opportunistic premises plumbing pathogens" have been recognized only more recently; Legionella pneumophila discovered in 1976, Mycobacterium avium, and Pseudomonas aeruginosa are the most commonly tracked bacteria, which people with depressed immunity can inhale or ingest and may become infected with.[35] These opportunistic pathogens can grow for example in faucets, shower heads, water heaters and along pipe walls. Reasons that favor their growth are "high surface-to-volume ratio, intermittent stagnation, low disinfectant residual, and warming cycles". A high surface-to-volume ratio, i.e. a relatively large surface area allows the bacteria to form a biofilm, which protects them from disinfection.[35]
When you need plumbing or HVAC services in Castle Rock, there’s only one choice to make: PRO Plumbing Service. With more than 2500 service calls per year, we are your trusted plumbing, heating, and air conditioning company. If you are looking for a family-owned and operated plumbing and HVAC company, our top-rated HVAC contractors and plumbers ready to assist.
I just had my pipe under the sink unclogged  and new pipes put in $600.00, then they flushed out the pipe from under the sink to the outside pipe $700.00, Total of $1.600.00, I thought that the price was high, I got the plumber from Home Advisors, not sure they had to do all they did but they said I needed the work done.  The same evening hike using the dishwasher I had a leak in one of the pipes they put in, they came back the next day to fix it. Don't know if I will use them again.. They were K&D kitchens.
Most plumbers wont mess with the septic tank. We deal mostly with components inside the house. Did you have a vent pipe in the yard (often looks like a candy cane made of PVC) before the repair but not after? If all he did was replace the line it shouldn't cause a smell inside the house. All plumbing fixtures inside the house should have properly functioning traps. Those traps would create and maintain a water seal against the sewer gases. You should have at least one vent through the roof to equalize pressures within the drainage system. This prevents positive pressures within the system (caused by fixtures discharging into the lines, ie toilet flush) from pushing gas out through the traps, and negative pressures (the waste in line will pull air behind it like your finger over the end of a straw) from sucking water out of the traps.
When a person has a blockage in their sewage system they often try to fix it themselves by adding an acid or a base such as Drano in an attempt to dissolve or dislodge the problem. These chemicals can get into the plumbers eyes [14]when the sewage is splashed during the repair. The plumbers skin during the repair does come into contact with the sewage water.[15] The owner of the toilet might not report to the plumber they have already tried Drano a highly caustic base .