City of Houston Reuse 3/10/2014 Page 2 of 27 State. A Bed and Banks permit basically provides for: 1. An entity to discharge water such as WWTP effluent into State Waters and retain ownership of that flow (or some portion of it); and 2. To divert that flow from the State Waters downstream from where it was discharged. The entity is essentially using the bed and banks of the river, stream, or bayou to convey its water from a point of discharge to where it can provide a beneficial use (diversion point). TCEQ issued Permit No. 5827 on May 11, 2011. The permit lists 32 City WWTPs with permitted discharge rates, and 14 authorized diversion points with maximum diversion rates. At the end of this section, Figure 1 maps the location of the 32 WWTPs; Figure 2 maps the permitted diversion locations. Table 1, below, lists the WWTPs that were investigated for this study. The Almeda Sims WWTP and Southwest WWTP were examined for direct reuse, while the other four WWTPs were only examined for potential flow contribution downstream in Brays Bayou. Table 2 lists the permitted diversion location and maximum diversion rate that was considered for this study. TABLE 1: CITY OF HOUSTON PERMITTED DISCHARGES Wastewater Treatment Plant Almeda Sims Southwest WCID2 111 Beltway Upper Brays Keegans Bayou
TPDES Permit # 10495003 10495037 10495095 10495111 10495116 10495119
Discharge (MGD) 28.00 60.00 7.20 13.34 18.00 23.10
Receiving Stream Houston Ship Channel Houston Ship Channel Keegans Bayou Houston Ship Channel Houston Ship Channel Houston Ship Channel
TABLE 2: CITY OF HOUSTON PERMITTED DIVERSIONS Diversion Location
Maximum Diversion Rate (cfs)
Maximum Diversion Rate (MGD)
Stream or Lake
Southwest WWTP
188.2
121.6
Brays Bayou
The tables appear to indicate that there is substantial reuse water available for diversion. However, there are several significant conditions that impact the amount of water that can actually be diverted on a reliable basis from the bayou. These conditions are listed below along with FNI commentary in italics.