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�I rFdecreaseorganic matter. The attached environmental fate data for DDT and its degradates documentor organic matter. Since most of the property has been in agricultural production, organicese soils would be assumed to be higher than in non-agricultural soils. However, the oil chemistry brought on by the environmental factors specified above, will definitely lead se in soil organic matter decomposition and subsequent DDT degradation. Final concentrations of DDT and its degradates in the play areas or garden areas of each new single family residence cannot be predicted, and probably will not exist after earthwork. It must be emphasized that ingestion data to determine adverse health effects from DDT, DDD, DDE is primarily based upon a "worst-case scenario' of a child eating specific volumes of soil each day. These children and this abnormality are called "pica children" because of their craving for unnatural food. Obviously, parents who may have children with this condition must prevent ingestion of soil by their children, thus greatly reducing the risk of DDT toxicology. The one square mile land area, or "section" bound by Valpico Road to the north, Linne Road to the south, Chrisman Road to the east and MacArthur Road to the west is commonly referred to as the "Valpico Section." Sources cnntrihntina n;rr�r�rhe groundwater under this section include t1II>�radient aericultural fertilizer inputs s�tiEsvems (oarticularly from sumps and pits), lawn/landscape fertilization, indigenous soil concentrations from decomposing— organic matter and ra actors decreasing a groan wa er a concen ration mcl3e e-3 m cation, groundwater movement (both vertical and horizontal), well pumping and well hydraulics, and cleaner water recharge from stormwater retention basins and the Wastewater Treatment Plant contributing a dilution effect. Therefore, if each of these sources and attenuating factors could be quantified on a mass balance basis, it may be that nitrate input is now roughly equivalent to output, or what could be regarded as equilibrium. Given that agricultural irrigation recharge is the largest single co tributor to groundwater nitr fitFeEieRSran since the surrounding land has been farmed for several eca es, itis assumed that the nitrate concentrations in the underlying groundwater should be much higher than those observed, if the attenuating factors were not significant. After project development, a percentage of the land surface will be impermeably covered with structures, concrete, and pavement. This will have an attenuating effect on the downward migration 4,of nitrate molecules from most of the subject property land that is, or has been in agricultural production. These impermeable surfaces will be traded for potential point sources of nitrate, specifically lawns and landscaping. Domestic irrigation recharge can account for 250 to 1,500 gallons of water/day/residence during the spring and summer months. Excessive lawn and landscape nitrogen fertilization, in combination with excessive watering can lead to nitrogen leaching and runoff to open areas and retention basins. Therefore, nitrogen fertilizer must be carefully applied to lawns, gardens and landscaping. Due to the existing nitrate problem in the un erying groundw_ater,. s'fow re e1 ase–intro�hzers s oh uT ed for lawn and landscape fertilization. This type of IZMU�zer is becoming more popular m the consumer market and should have a long-term beneficial effect on nitrate impact to groundwater, especially in areas such as the Valpico Section. The following calculations show the cumulative areal nitrate loading from wastewater originating Lwttewatser ject parcels, as if they were on conventional septic systems. These calculations illustrate ate loading prevention since residential development of the property will be under reatment: 9 Chaney Consulting