Dallas Water Utilities (DWU) has in excess of 4,200 miles of sewer line. This project aimed at reducing the number of blockages in sanitary sewer lines caused by FOG (Fats, Oils and Grease). FOG blockages present a concern to both human health and the environment. DWU realized that by taking a proactive approach and developing a comprehensive FOG program these types of blockages could be mitigated. This FOG program included identifying "hot spots" for proactive line cleaning, changing city ordinances to comply with HB 1979 and developing an educational program. DWU has reduced FOG blockages in the sanitary sewer system by 93% over five years.
The DWU FOG program takes a holistic approach to addressing FOG issues and involves three major types of activities: 1.) preventive maintenance, 2.) regulatory enforcement, and 3.) outreach and education.
PREVENTIVE MAINTENANCE: DWU's Wastewater Collection Division cleans at least one third or 1,400 miles of our wastewater lines each year. Hot spots - locations in the sewer system with recurring issues - are cleaned more frequently as part of the Hot Spot Preventive Maintenance Program. Hot spots include pipes having grease, or debris accumulation, inverted siphons, or commercial areas with multiple restaurants. Additionally, direct mailings or door hangers are distributed to mail codes in the area around a FOG-related sanitary sewer overflow (SSO) within 24 hours after an incident so citizens know that putting FOG down the drain causes these sewer problems.
REGULATORY ENFORCEMENT: DWU changed the City ordinances for Food Service Establishments (FSEs) to adhere more closely to state laws, such as the Texas Commission on Environmental Quality's "Model Standards for Grease Management," including the 90 day 25% solids rule to enable FSEs to better utilize the treatment of their grease collection devices (GCDs). Additionally, field staff were added to monitor cleaning frequencies of GCDs. A new innovative data software package (XC2) was purchased that enables us to better track and monitor cleaning frequencies by utilizing OCR (Optical Scanning Characteristic) technology that we helped develop. The additional staff and software helped reduce the amount of FOG that would enter the sanitary sewer.
OUTREACH & EDUCATION: The educational program targets apartment complexes, schools and FSEs. Apartments generate a large amount of FOG according to the DWU Wastewater Collections Division. DWU works with apartment managers and the Apartment Association of Greater Dallas (AAGD) to educate apartment residents. DWU's "Cease the Grease" campaign offers booths and presentations at the annual AAGD Trade Show and the annual City of Dallas SAFE Symposium - a mandatory apartment managers conference. DWU provides apartment managers with bilingual literature, presentations, grease bags and FOG recycling for their properties. DWU also worked with the North Texas Grease Abatement Council to develop an educational video targeting apartment residents. The video won the National Association for Clean Water Agencys 2010 National Environmental Achievement Award. School outreach is also part of the "Cease the Grease" campaign. Depending on the grade level hands-on activities, story cards 3-D models, and videos are used to educate children about the Urban Water Cycle and FOG impacts. Students also receive FOG collection kits to take home as part of FOG recycling drives. The collected FOG is transformed into biodiesel. FSE outreach involved educational posters and brochures, and forming partnerships. Educational posters and brochures in English, Spanish, Vietnamese and Mandarin were developed to inform FSEs about the city's GCD requirements. DWU has also worked with the Greater Dallas Restaurant Association (GDRA) on its educational efforts and with other cities in the region to develop an educational video.
Total Cost Savings: $1,300,000.00
Comments: A large part of the City's savings on this program come from avoided cost of treating FOG from FSEs. Additionally, the City has saved an average of $40,000/year on avoided FOG-related SSOs. The number of FOG SSO incidents fell from 112 in fiscal year 2005-'06 to 8 in fiscal 2009-'10. The cost of responding to an SSO and the follow up cleaning, inspection and reporting has been estimated at $2,000 per SSO. An additional savings in avoided repeat and "hot-spot" sewer line cleanings have not yet been estimated.
Details of Reductions
13,500,000.0 - Gallon of
Fat, Oils and Grease
Additional Information :
DWU provides water and wastewater services to a 699 square mile area. As part of our service, DWU treats 74 billion gallons of wastewater annually (FY 06-07). DWU's mission is to be an efficient provider of superior water and wastewater service and a leader in the water industry. As part of this mission, DWU adopted a proactive & comprehensive program to reduce FOG-related blockages in the sanitary sewer thus enabling us to provide better service to our customers. As part of this program an innovative educational component was added that reaches out to all of our customers to increase their knowledge and awareness of the impact that FOG can have on a largely unseen part of their daily lives - the sanitary sewer. The total cost savings of this program are hard to calculate due to the nature of the wastewater system but DWU believes that the investment has been a wise one.