SITE INFORMATION AND CORRESPONDENCE

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• 0 Bert E. Van Voris - 21 - 17 September 2004 Supervising Engineer approximate 1-foot depth by discing."32 While the RWD uses the results of one sample of leaves to characterize the quality of this waste for nitrogen (1.4%), calcium (2.29%), iron(470 mg/kg), and other mineral constituents, it does not identify (at least as far as I could tell) the amount of olive leaves typically discharged annually or what kind of loading of nitrogen and other constituents this represents. Prior to 2001, Musco discharged olive leaves to Park West. Figure 10 depicts the historic Park West olive leaf discharge area and two areas where olive leaves were discharged in 2002: a fallow area north of eastern portion of South Ridge and an area within the western portion of South Ridge West. South Ridge soils prior to leaf application below 30"bgs contain little nitrogen(total nitrogen less than 0.05% and nitrate-nitrogen less than 1 mg/kg). Forty-five days following leaf application, ammonia- nitrogen levels more than doubled(to a maximum of 4.3 mg/kg) and nitrate-nitrogen levels increased slightly. No data was provided for total nitrogen content of South Ridge soil following leaf application. Because nitrate concentrations did not increase 45 days following leaf application,the RWD concludes, "it appears that the olive leaves did not contribute to soil nitrate concentrations within the first 45 days after application."33 The RWD concludes, despite limited data,that the leaf discharge should be allowed to continue. It states, "Musco is not degrading soil quality in terms of nitrogen by applying olive leaves after harvest."34 Comment: Figure 10, Olive Leaf Application Area Soil Sample Locations, denotes two areas where leaves were applied in 2002. Also,the leaf application area that the RWD describes as"the northeast section of South Ridge field" is actually north of this field. In April 2004, I visited Musco unannounced and, accompanied by Mr. Dennis Leikam, inspected where leaves had been discharged north of South Ridge. I observed it to be a large expanse of composting leaves, approximately 12-inches thick. I saw no evidence that the leaves had been disced into the soil. The RWD does not contain sufficient information to describe how the leaf discharge will be performed or what loadings of waste constituent it represents. Data provided for South Ridge before leaf application includes nitrate, ammonia, and total nitrogen, while the data provided for post-leaf application only includes nitrate and ammonia. Most of the applied nitrogen is organic and will slowly mineralize to ammonia and nitrify to nitrate. It is not possible to evaluate the total nitrogen loading due to the leaf application because Table 9 does not provide total nitrogen for post-application soils. Therefore, it is not possible to evaluate whether the loading to South Ridge soils is excessive and will cause excessive nitrate in the soil profile as evidenced in Park West soils. In order to conclude the leaf application practices are acceptable, the RWD should provide supporting data consisting of the nitrogen loading to each leaf application site and the total nitrogen in post- application soils. Until evidence is provided to demonstrate otherwise,the leaf discharge—as conducted to date—appears to load soils with excessive nitrogen and, as such, is not protective of groundwater quality. Until this matter can be resolved, olive leaves should be hauled offsite to a permitted composting facility for proper treatment and disposal. Additionally, Musco should describe either in the RWD or under separate cover what long- term measures it would implement to decrease the concentration of nitrate in Park West soils