| Total requests for May 2011: 591 |
| Unique requests | Total requests | Query | Documents returned |
| 9 | 10 | global warming | 1 |
| 5 | 20 | deforestation | 5,799 |
| 4 | 5 | compost | 2 |
| 4 | 5 | air pollution | 14 |
| 4 | 4 | videos | 5 |
| 4 | 4 | climate change | 2 |
| 3 | 7 | biomes | 0 |
| 3 | 5 | rain forest | 25,203 |
| 3 | 5 | landfills | 1 |
| 3 | 5 | Acid Rain | 6 |
| 3 | 3 | water pollution | 3 |
| 3 | 3 | recycle | 22 |
| 3 | 3 | Sanitation | 0 |
| 2 | 19 | games | 179 |
| 2 | 10 | OPEC | 0 |
| 2 | 6 | oil spill | 181,503 |
| 2 | 5 | oil | 3 |
| 2 | 3 | trees | 4 |
| 2 | 3 | pollution | 2 |
| 2 | 3 | hair gel | 0 |
| 2 | 2 | water treatment | 2 |
| 2 | 2 | green car | 2 |
| 2 | 2 | florida | 4 |
| 2 | 2 | dioxin | 0 |
| 2 | 2 | carbon footprint | 2 |
| 2 | 2 | carbon cycle | 2 |
| 1 | 21 | strategic petroleum reserve | 10,618 |
| 1 | 13 | newt | 6,191 |
| 1 | 12 | 0358 | 8,265 |
| 1 | 10 | jaguar | 22,199 |
| 1 | 6 | rainforest | 20,999 |
| 1 | 5 | transportation | 3 |
| 1 | 4 | soup kitchen | 0 |
| 1 | 4 | Pueblo colorado | 3,824 |
| 1 | 4 | 94303 | 26,500 |
| 1 | 3 | videos DVDs | 37,332 |
| 1 | 3 | population biology | 35,666 |
| 1 | 3 | plant protectors club | 35,001 |
| 1 | 3 | planet protectors | 40,334 |
| 1 | 3 | nonrenewable energy | 121,999 |
| 1 | 3 | haze | 2 |
| 1 | 3 | John d. rockefeller | 0 |
| 1 | 3 | 6 energy source | 2 |
| 1 | 3 | 1890 gasoline demand | 0 |
| 1 | 2 | why do people litter | 0 |
| 1 | 2 | what does opec stand for | 0 |
| 1 | 2 | watchlist | 53,999 |
| 1 | 2 | retra | 0 |
| 1 | 2 | resource stripping | 0 |
| 1 | 2 | project plan | 4 |
| 1 | 2 | population | 2 |
| 1 | 2 | polar | 0 |
| 1 | 2 | plants | 55,502 |
| 1 | 2 | petroleum | 0 |
| 1 | 2 | nitrates | 0 |
| 1 | 2 | nitrate phosphate tests | 0 |
| 1 | 2 | niger river | 2 |
| 1 | 2 | new york | 51,001 |
| 1 | 2 | nasty foods | 0 |
| 1 | 2 | invasive | 4 |
| 1 | 2 | how to recycling for kids | 4 |
| 1 | 2 | how much water dose a person use per day | 110 |
| 1 | 2 | hazardous waste landfills | 766 |
| 1 | 2 | global warming animation | 2 |
| 1 | 2 | data sheets | 0 |
| 1 | 2 | cosmetics | 51,999 |
| 1 | 2 | coal | 1 |
| 1 | 2 | chemical safety | 52,002 |
| 1 | 2 | asbestos | 0 |
| 1 | 2 | art | 2 |
| 1 | 2 | animal | 2 |
| 1 | 2 | alviso environmental education center | 0 |
| 1 | 2 | algebra 1 | 0 |
| 1 | 2 | air stripping | 1 |
| 1 | 2 | Oil enegy sources | 8 |
| 1 | 2 | OEC | 59,999 |
| 1 | 2 | It's My Environment video | 2 |
| 1 | 2 | 45346 | 0 |
| 1 | 1 | yeager | 0 |
| 1 | 1 | words to songs | 2 |
| 1 | 1 | woonsocket | 0 |
| 1 | 1 | wizz ball | 0 |
| 1 | 1 | windmills | 0 |
| 1 | 1 | where dose drinking water come from | 0 |
| 1 | 1 | what was the main oil use before the 1890's | 0 |
| 1 | 1 | what are interesting things about plastic | 0 |
| 1 | 1 | wetland | 2 |
| 1 | 1 | watershed | 2 |
| 1 | 1 | water | 4 |
| 1 | 1 | water scarcity | 0 |
| 1 | 1 | water purify | 0 |
| 1 | 1 | water monitoring | 0 |
| 1 | 1 | water filtration | 0 |
| 1 | 1 | water energy | 2 |
| 1 | 1 | water cycle | 4 |
| 1 | 1 | waste water | 3 |
| 1 | 1 | waste sort | 3 |
| 1 | 1 | waste management | 4 |
| 1 | 1 | waste disposal | 8 |
| 1 | 1 | uv education | 4 |
| 1 | 1 | treatment | 2 |