1. ERT 468 SURFACE WATER Surface Water Sources and Quality
MDM AIMI ATHIRAH AZNAN
LECTURER
BIOSYSTEMS ENGINEERING PROGRAM
SCHOOL OF BIOPROCESS ENGINEERING, UniMAP

2. INTRODUCTION Agricultural Water
The water that may come into contact with the edible portion of a crop during growing, harvesting, processing and packing, according to the produce safety rule.
It includes water used for farming or packing operations, such as the water used for:
irrigation of crops
pesticide or fertilizer applications
preventing frost damage or crop dehydration, and
washing or cooling of produce
INTRODUCTION

3. Surface water is water on the surface of the planet such as in a river, lake, wetland, or ocean.
Replenished by precipitation, naturally lost through discharge to the oceans, evaporation and subsurface runoff.
Surface Water

5. Typical sources of agricultural water from surface water include:
Rivers, streams, and irrigation ditches
Open canals
Impounded water such as ponds, reservoirs, and lakes
Surface Water Sources
 Estimated Use of Water in the US in 2000
(Figure courtesy of US Geological Survey)

6. Rivers, streams and ponds (surface water sources) are an alternate source of irrigation water to wells or a municipal system. They can be less expensive to develop but generally have more problems in water quality and quantity.

7. Surface water is subject to contamination from a number of sources such as sediment, chemicals and plant growth.
These may need to be removed to make the water usable in an irrigation system. 
Tests for total suspended solids, volatile suspended solids, total dissolved solids, pH (pH 6 - pH 7), conductivity and some of the key elements should be the first step in evaluating a source of surface water.
Water Quality for Crop

8. Contaminants
Sediment- suspended particles such as, soil, clay and sand from runoff from adjacent agricultural land, construction sites and bank erosion.
Cause: Affect the operation of pumps, piping and nozzles. High levels of particles can reduce the life of pumps and clog sprinklers.
Solution:
Water samples taken at different times of the year and after a heavy rainfall can help to determine the concentration of suspended solids.
The type and size of filters will vary with the size and amount of the particles and the type of irrigation nozzles used.
Multiple filters may be required.
A common filter for dirty water is self flushing.
When the pressure difference between the intake and exit is above a certain level, the filter will be flushed and water dumped.

9. Factors for algae development
Contaminants
2. Algae and bacteria- 
Algae:
High light levels
High temperature
Carbon dioxide
Nitrogen
Phosphorus
Trace elements/micronutrient
Solution: A pump or compressor aerator that circulates the water and introduces oxygen may be needed.
Recently wind and solar powered aerators have become available.
Bacteria:
Slime caused by the presence of bacteria can clog irrigation systems.
Development of these may be from hydrogen sulfides, iron bacteria or manganese present in the water.
Factors for algae development

10. Contaminants
3. Animal organisms- create blockages in irrigation pipes and nozzles.
Example:
Protozoans
Zooplanktons
Small crustacean
Fish
Water fleas
Water mites
Solution: Filtration is needed.

11. Contaminants
4. Chemical sediments- surface water is likely to have the presence of chemicals from runoff of adjacent fields or from illegal industrial waste.
Harmful chemicals such as chlorine, boron and other salts that are found naturally in the soil.
Example: One of the most common pollutants found in New England streams is high nitrate levels from manure application and fertilizer used on dairy farms.
It is also possible to have water that has a harmful level of herbicides from agricultural fields near the stream.

12. Water Quantity for Crop
Surface water sources are dependent on runoff from adjacent land or from ground water springs.
These are dependent on rainfall rates that vary from year to year. 
Water use rates are related to transpiration and evaporation.
Irrigation water replaces the plant water use.
The details on calculation will be discussed in Crop Water Demand topic.
Water Quantity for Crop

13. Farm Water Storage System
Pond
Farm Water Storage System
Tank Water Storage

14. Farm Water Storage System: Pond
Benefit:  
Improve agricultural water security through the capture, storage, and provision of water for irrigation.
Supply a water source for frost protection, recharge groundwater, and provide a wide range of additional economic and environmental benefits.
Pumping from a pond uses much less energy than pumping groundwater. 
Ponds can be used to settle and filter farm runoff, capturing soil that can be returned to fields and filtering pollutants and particulates that would otherwise negatively impact the broader ecosystem.
Water in Pond:
Ponds can be filled by rainfall and serve to collect runoff from higher in the watershed.
Alternatively, farm ponds can be filled with tailwater from irrigation, which can then be recycled.

15. Farm Water Storage System: Pond
Applications:  
Ponds do not function well on sandy or other highly porous soils; works best on clayey soil.
The size of ponds, the water demands of the crop, and the acreage of irrigated land all determine the efficacy of ponds.

16. Farm Water Storage System: Tank Water Storage