HomeMy WebLinkAbout1980-02-19; City Council; 6176; Shadow Ridge satellite sewer treatment plant- CITY OF CARLSBAD W
Initial:
Dept. Hd,
C. Attv,
AGENDA BILL NO.
DATE : February 19, 1980
/o/ 7 6
DEPARTMENT : Council C. Mgr.
Subject : SHADOW RIDGE DAON
Satellite Sewer Treatment Plant - Buena Sanitation District
Statement of the Matter
Vice Mayor Skotnicki has requested discussion of the subject matter and instructions from Council to JAC representative regarding connection to Encina Water Pollution Control Facility.
The JAC representatives will furnish such information as may be
necessary to make a decision on this matter.
Exhibit
A. Information for discussion
- Council Action:
2-19-80 Council continued the matter to the meeting of February 20, 1980.
2-20-80 It was consensus of Council that JAC representatives Skotnicki and Casler
advise JAC of Council approval of Buena connections to Encina upon the same conditions as those required of LCWD.
c
EXHIBIT A - INFORMATION FOR DISCUSSION
Shadow Ridge Daon Satellite Sewer Treatment Plant - Buena Sanitation District
The Buena Sanitation District has requested the Encina Joint
Advisory Committee (JAC) to authorize their proposal to send suspended solids (primary and secondary sludge) from their Shadow Ridge plant (1.0 million gallons per day capacity) along
with normal sewage flows to the Encina Water Pollution Control
Facility.
stabilized in Encina's digestors and disposed of with the sludge
normally generated at Encina.
The suspended solids would be removed at Encina,
The reasoning behind Buena's request is that by shipping solids to Encina, they will experience considerable savings both in initial capital construction costs (they won't build any digestors) and in
annual operations costs (cheaper to treat at Encina).
Buena proposed to start operating at the plant by diverting 250,000
gallons per day from sewage flows normally routed to Encina.
units will be constructed at the rate of 400 per year for 10 years. Flow from the new units will go to Encina until the 250,000 gpd diversion has been offset. It is estimated this will take 2 1/2 years. From then on all new units would go to the Shadow Ridge plant. The amount of solids going to Encina will increase on two accounts. For the first 2 1/2 years the addition will be partly due to new units and partly due to the additional treatment given to the diverted flow (Encina is a primary plant, Shadow Ridge is a secondary plant). After 2 1/2 years, all additional solids will be attributable
solely to new units.
additional solids that can be expected at Encina if Buena's request
is approved.
New
The following chart shows the quantity of
END OF YEAR
0
1
2
3 4
5
6
7
8
9
10*
NEW HOMES
0
400 800
1200
1600
2000
2400
2800
3200
3600
4000
ADDITIONAL SOLIDS
362.5 lbs.
507.9 lbs.
652.5 lbs.
870 lbs.
1160 lbs.
1450 lbs.
1740 lbs.
2030 lbs. 2320 lbs.
2610 lbs.
2900 lbs.
The Buena Sanitation District currently contributes approximately 750
to 800 lbs. of suspended solids per day to Encina. Total suspended solids to Encina from all sources is approximately 20,000 lbs. per day.
* By this time Encina will probably be flowing at the full rated capacity
of 18 MGD and will be furnishing in the neighborhood of 40,000+ lbs.
of solids per day.