The low-redshift (z < 1) IGM probes the last eight-billion years of metal enrichment from galactic feedback processes. Outflows and mergers return to the IGM enriched material for future generations of galaxies and stars. The signature of this process is etched in the recycled gas: metallicity, abundances, density, distribution, etc. We conducted the largest survey for C IV and/or SiIV systems at z < 1, and we compare our results to those from high-redshift (1.5 < z < 6) studies. For example, we present the frequency distribution f(N) and mass density of C IV and SiIV absorbers in the HST archival spectra of 49 quasars. The changes in the properties of the low-redshift systems, compared to the high-redshift ones, indicate that CIV and SiIV more commonly trace circumgalactic gas at z < 1.