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9 718 CHAPTER 11: Intermittent and Recirculating Packed-Bed Filters TABLE 11-2 Historical performance of Massachusetts ISF systems' Loading BODS BODS rate, influent, effluent, Location Period gallff-d mglt. mg/L Brockton 1897-1903 0.9 314 6.2 Framingham 1893-1902 259. 6.3 Gardner 1893-1902 2.8 122 11.4 Leicester 1897-1903 1.9 321 13.1 Marlborough 1894-1903 1.7 139 9.5 Natick 1897-1903 1.2 82 7.7 Spencer 1898-1903 1.4 116 6.9 'Adapted in part from Mand and Peeples(1991). Lagoon upgrading applications. The use of ISF systems to treat lagoon ef- fluents was reported by Marshall and Middlebrooks(1974)and by Rich et al.,(1995). Additional details on the use of sand filters for the treatment of lagoon effluent are discussed in Chap. 8. Treatment Performance Intermittent sand filters, with frequent small doses, produce a high-quality efflu- ent that is low in BOD, TSS, turbidity, and ammonia. Properly designed ISFs (e.g., lightly loaded, small doses, and numerous orifices) have proven very effective in the removal of total and fecal coliform'and viruses (Emerick et al., 1997). Historical data on the long-term removal of BOD and ammonia nitrogen by ISFs are presented in Tables 11-2 and 11-3, respectively.The performance of ISF systems studied from 1949 to 1997 is summarized in Table 11-4. ISF systems are also effective in remov- ing bacteria, with 99.9 percent removal measured: Fecal coliform removal for ISF systems is summarized in Table 11-5. The removal of virus (F+ specific coliphage) _ as a function of the dosing rate is illustrated in Fig. 11-7, presented previously. TABLE 11-3 Historical performance of Massachusetts ISF systems for ammonia nitrogen removal" Loading Ammoniamg/L Effluent Percent rate, , gnitrate-N, nitrogen Location Period gaVW.d Influent Effluent mg/L removal Brockton 1897-1903 0.9 40.7 1.5 12.9 77 Framingham 1893-1902 27.3 2.7 11.6 74 Gardner 1893-1902 2.8 21.2 7.5 5.5 58 Leicester 1897-1903 1.9 31.8 9.2 9.0 55 Marlborough 1894-1903 1.7 30.9 7.9 8.1 62 Natick 1897-1903 1.2 12.4 2.3 4.9. 59 Spencer 189&-1903 1.4 16.0 2.1 6.9 65 'Adapted in part from Mand and Peeples(1991).