The United States has made tremendous advances in the past 25 years to clean up the aquatic environment by controlling pollution from industries and sewage treatment plants. Today, nonpoint source pollution remains the Nation's largest source of water quality problems. Nonpoint source (NPS) pollution occurs when rainfall, snowmelt, or irrigation runs over land or through the ground, picks up pollutants, and deposits them into rivers, lakes, and coastal waters or introduces them into ground water. The most common NPS pollutants are sediment and nutrients. Other common NPS pollutants include pesticide, pathogens, salts, oil, grease, toxic chemicals, and excess fertilizer.
The watershed approach is one way to determine the effectiveness of management techniques. It looks at a waterbody but also the entire area, including all the potential sources of pollution, that drains into it. Water conservation uses technologies that limit water use in the bathroom, kitchen, laundry room, lawn, driveway, and garden, thereby reducing the demand on existing water supplies and limiting the amount of water runoff. A more technical approach can be used which includes the implementation of best management practices ( BMP). These are pollution control measures that can be used to prevent or reduce the impacts from activities that may cause water pollution. Examples of BMPs include, erosion control techniques like silt fencing, establishment of riparian (vegetated) zones next to waterbodies to filter out pollutants, and xeriscapei landscaping which incorporates native species, proper irrigation, mulches, and appropriate maintenance schedules. Many local groups organize volunteer monitoring efforts which provide information that can help government agencies understand the magnitude of NPS pollution.
| (circle each one) | |
| Nonpoint Source | Runoff |
| Watershed | Monitoring |
| Conservation | Environment |
| Water | Pollution |
| BMP | Nutrients |
| Sediment | Pesticide |
| Fertilizer | Xeriscape |
| Riparian | Erosion |
A N O N P O I N T S O U R C E
N P U A I R D E G H F A I O P
L T O T N E M I D E S W P A A
O W A T R N B K C M L E A G C
N A F D U I Y F F O N U R B S
O T E W O T E R B W T N I C I
I E R Y L P M N R G C D A G R
T R T P O L L U T I O N N A E
A S I E M S T D W S R I F S X
V H L S K B W K J U R S L N C
R E I T C T U A S O I M R O M
E D Z I P L V O T A W Z H I F
S E E C M F H I R E D L M S A
N E R I A N N K G P R H P O J
O D I D V O C M D J T J E R B
C T N E M N O R I V N E T E W
|