The short answer is simply that it depends. You will need to look at a few factors first before you consider trying to save the wet carpet. Please check the following:
How Old is the carpet?
You need to consider the costs of replacement vs recovery. If you are planning to replace your carpet anyway, you may consider simply removing the wet carpet. Just remember that simply removing the carpet will not always fix the problem. You need to ensure your walls and subfloor has been dried property or you could expect future mould growth.
How Long has the Carpet been Wet?
Generally, once there is mould growth on the carpet, it should be replaced. Mould can start to grow within 48 hours. Therefore If the carpet has been wet for a week, you could effectively expect some sort of microbial growth. If you can smell a musty mouldy smell, you could assume there is some sort of mould growth and that it should be thrown away anyway.
Sewage Affected Carpet
We get a lot of enquiries from people who want to save the sewage-contaminated carpet. We will rarely attempt to restore sewage affected carpet as it can be costly, ineffective and simply dangerous. There are a variety of health concerns involved where sewage and detritus are present.
In this case, we opt to cut out the affected sections, then treat the subfloor as well as to conduct a hard surface clean to the area.