A. COLLECTION SYSTEM
The wastewater collection system can be identified as separate components, one serving the City of Port Aransas and the other serving the remainder of Mustang Island, including the Terramar tracts. The two components are interconnected and the flow is transported by a series of lift stations to the District’s wastewater treatment plant.
The overall collection system consists of force main and gravity lines varying in diameter from 4″ to 24″, including 21 lift stations, which are an essential element of design in flat terrain areas such as Port Aransas. The following table denotes each lift station and describes the existing pumps and their available pumping capacity.
TABLE VIII-1: Existing Lift Stations
|#||LOCATION||SUBMERSIBLE PUMPS||PUMP CAPACITY|
|1||La Concha #1||2||10 hp – Flygt||501|
|2||La Concha #2||2||12 hp – Flygt||1026|
|3||Admiral’s Row||2||3 hp – Flygt||384|
|4||Lost Colony||2||10 hp – Flygt||466|
|5||Port Royal||2||15 hp – Flygt||560|
|6||Gulf Waters||2||5 hp – Flygt||405|
|7||LS #7||N/A||– – –|
|8||Beachwalk||2||20 hp – Flygt||809|
|9||Pioneer RV||2||15 hp – Flygt||513|
|10||Newport||2||20 hp – Flygt||1068|
|11||Island Moorings||2||15 hp – Flygt||560|
|12||Airport||2||10 hp – Flygt||727|
|13||Cemetery||2||20 hp – Flygt||943|
|14||Avenue G @ Alister||1|
|40 hp – Flygt|
20 hp – Flygt
|15||Avenue G @ 11th St.||2||3 hp – Flygt||384|
|16||Channel Vista||2||5 hp – Flygt||400|
|17||Dunes||2||3 hp – Flygt||384|
|18||Private Marina||2||3 hp – Flygt||384|
|19||Municipal Harbor||2||3 hp – Flygt||313|
|20||Cotter||2||20 hp – Flygt||809|
|21||WWTP||2||10 hp – Flygt||466|
The three largest lift stations, which are responsible for collecting the flow from various areas of the service boundary and delivering it to the treatment plant, are as follows:
- Beachwalk – Lift Station #8, is located south of Port Aransas and equipped with three submersible pumps rated at 20 Hp and 809 gpm. With all the other pumps running in the system, this lift station is able to deliver approximately 893.1 gpm (446.55 gpm/pump)
- The Cemetery Lift Station (LS #13) is equipped with two 20 Hp submersible pumps rated at 875 gpm. It is currently operating at 638.63 gpm when all pumps are on.
- The lift station at Avenue G and Alister Street is equipped with three, 40 Hp submersible pumps; two are rated at 1400 gpm and the other at 2315 gpm. This triplex is producing a total of 2167.6 gpm when all other pumps are operating (1083.8 gpm/pump).
The combined capacity of these three lift stations is 5.33 MGD, which equates to 94.45% of the two-hour peak hydraulic capacity of the existing wastewater treatment plant.
B. WASTEWATER TREATMENT PLANT
The wastewater treatment plant is located approximately 1/4 mile west of the intersection of Sixth Street and Avenue I, at the end of Ross Avenue in the City of Port Aransas, Texas. It is operated under TCEQ’s TPDES Permit No.WQOOI0846001 and discharges into the marsh area west of the plant, then into Corpus Christi Bay in water segment No. 2481 of the Bays and Estuaries. The annual average design hydraulic capacity of the plant is 1.88 MGD with a
two-hour peak of 3,917 gpm (5.64 MGD).
The plant consists of two separate treatment units: Unit 1 has capacity for 60% of the design flows and Unit 2 the remaining 40%. Flow is presently split 50:50 between the units until flow rate approaches the design capacity of the plant. Unit 1 is an oxidation ditch type aeration basin with horizontal rotors providing the air and Unit 2 is a circular tank with diffused air provided by blowers. Both units use complete mix activated sludge for the treatment process. The treatment plant consists of fine screening and degritting followed by biological treatment using activated sludge (complete mix). followed by secondary clarification, chlorination and dechlorination. Settled solids from the clarifiers is periodically wasted to the Aerobic Digesters where it is thickened and stabilized aerobically and then all sludge is dried on sludge drying beds. Final sludge disposal is to a sanitary landfill.
The current discharge permit has a 10 milligram per liter (mg/l) limit of carbonaceous biochemical oxygen demand (CBOD5), 15 mg/llimit on total suspended solids (TSS), 2 mg/l of ammonia nitrogen (NH3) and a minimum 5 mg/l of dissolved oxygen (DO).
1812 State Highway 361, Suite F
Port Aransas, TX 78373
8am–12pm and 1pm–5pm
Mon. – Fri.
For water leaks or other emergencies, leave a message at 361-749-5201.
On call personnel will contact.