| Total requests for May 2011: 1,568 |
| Unique requests | Total requests | Query | Documents returned |
| 19 | 32 | epanet2 | 137,246 |
| 9 | 11 | swmm 6 | 77,900 |
| 5 | 7 | epa methods | 52,642 |
| 5 | 6 | job | 66,016 |
| 4 | 6 | effect on marine life in the port of long beach | 69,216 |
| 4 | 4 | polystyrene | 66,500 |
| 3 | 10 | Arsenic | 50,510 |
| 3 | 8 | Pet | 76,575 |
| 3 | 7 | traci | 59,628 |
| 3 | 7 | grease interceptor | 57,214 |
| 3 | 7 | epa600r-00008 | 67,771 |
| 3 | 5 | PET bottle | 71,540 |
| 3 | 4 | tutorial | 64,625 |
| 3 | 4 | plastic | 55,875 |
| 3 | 4 | paper | 60,225 |
| 3 | 4 | landGem | 64,225 |
| 3 | 4 | ap42 | 52,574 |
| 3 | 4 | EPA 625R-00008 | 56,875 |
| 3 | 3 | sustainable | 56,633 |
| 3 | 3 | recycle | 54,033 |
| 3 | 3 | polycarbonate | 65,400 |
| 3 | 3 | ozone | 70,400 |
| 3 | 3 | epa42 | 35,133 |
| 3 | 3 | copper | 55,366 |
| 3 | 3 | bioscreen | 61,200 |
| 3 | 3 | air quality | 133,566 |
| 3 | 3 | acid rain | 55,766 |
| 2 | 4 | PM2.5 | 13,474 |
| 2 | 3 | transient | 63,133 |
| 2 | 3 | model | 63,800 |
| 2 | 3 | glossary | 54,566 |
| 2 | 3 | en2setup.exe | 0 |
| 2 | 3 | aermod | 59,233 |
| 2 | 3 | Polylactic acid | 68,433 |
| 2 | 3 | EPANET download | 73,433 |
| 2 | 2 | water reuse | 56,300 |
| 2 | 2 | water pollution | 318,500 |
| 2 | 2 | traci.exe | 53,850 |
| 2 | 2 | thermal desorption | 57,700 |
| 2 | 2 | south carolina | 61,250 |
| 2 | 2 | screen | 55,850 |
| 2 | 2 | q cost | 50,100 |
| 2 | 2 | pencil | 52,500 |
| 2 | 2 | packaging | 61,250 |
| 2 | 2 | method 5 | 52,450 |
| 2 | 2 | lead | 64,600 |
| 2 | 2 | graphs | 56,400 |
| 2 | 2 | grant | 62,550 |
| 2 | 2 | employment | 26,253 |
| 2 | 2 | clothes | 69,900 |
| 2 | 2 | clean water act | 61,800 |
| 2 | 2 | cement | 60,950 |
| 2 | 2 | butcher shop wastewater | 61,100 |
| 2 | 2 | bioremediation | 65,850 |
| 2 | 2 | batteries | 49,900 |
| 2 | 2 | batteries+recycling | 49,900 |
| 2 | 2 | air sampling | 61,900 |
| 2 | 2 | air pollution | 59,300 |
| 2 | 2 | activated carbon | 50,150 |
| 2 | 2 | What can I personally do to Help with Green Chemistry | 52,250 |
| 2 | 2 | SSOAP | 56,300 |
| 2 | 2 | Pressure Distribution | 70,950 |
| 2 | 2 | Iron | 56,050 |
| 2 | 2 | 504 | 52,700 |
| 2 | 2 | 40 CFR 257 | 70,150 |
| 1 | 13 | camelina | 25,590 |
| 1 | 9 | air quality index | 69,599 |
| 1 | 9 | WTP | 56,888 |
| 1 | 8 | paper products | 61,940 |
| 1 | 7 | sage | 57,828 |
| 1 | 7 | asbestos mine remediation | 47,647 |
| 1 | 7 | SWMM5 download | 41,514 |
| 1 | 7 | EPA drinking water lab manual | 61,257 |
| 1 | 7 | 81121 | 65,657 |
| 1 | 6 | steel | 55,033 |
| 1 | 6 | network example | 57,016 |
| 1 | 6 | fracking | 54,000 |
| 1 | 6 | b2. sampling method requirements | 42,616 |
| 1 | 6 | Evaluation of Steel Flasks for Long-Term Storage of Elemental Mercury: Chemical Compatibility Metallographic Assessment | 67,933 |
| 1 | 5 | vapor intrusion modeling | 53,900 |
| 1 | 5 | metals immobilization in soil | 59,260 |
| 1 | 5 | in situ chemical oxidation | 50,229 |
| 1 | 5 | examples applications swmm5 | 60,200 |
| 1 | 5 | desert value | 42,200 |
| 1 | 5 | ccr reports | 54,960 |
| 1 | 5 | Renovation water pipes | 70,820 |
| 1 | 4 | water storage | 57,975 |
| 1 | 4 | sustainable productionmanufacturing | 34,650 |
| 1 | 4 | questa | 80,550 |
| 1 | 4 | ord facets | 42,525 |
| 1 | 4 | milk powder | 26,925 |
| 1 | 4 | metal sulfide | 41,915 |
| 1 | 4 | extraction de materials primes | 65,750 |
| 1 | 4 | QSAR models | 53,400 |
| 1 | 4 | Petrex | 68,000 |
| 1 | 4 | Assimilableganic carbon | 50,600 |
| 1 | 4 | AERMOD Software | 38,925 |
| 1 | 3 | water quality standard | 79,866 |
| 1 | 3 | vapor pressure | 29,566 |
| 1 | 3 | vapor intrusion | 52,566 |
| 1 | 3 | usepa 2007 nanotechnology | 55,000 |