The Napa Sanitation District Collection System Department (NSDCSD) provides wastewater collection and sewer line repair and maintenance services to more than 33,000 homeowner and business connections. NSDCSD operates remotely from the Imola Corporation Yard and Administration Office located at 935 Hartle Court, Napa, CA 94559. The Collection System Department has 13 employees whose job is to ensure that 250 miles of underground pipeline (sewers), which vary in size from 4" to 66" in a 23 square mile area, are able to collect and transport wastewater to NSD's Soscol Water Recycling Facility. The Collection System Department also maintains over 33,143 sewer laterals and 5,651 manholes.

Preventative Maintenance Scheduling System
NSD has a planned schedule for cleaning sewer lines that are highly susceptible to root intrusion, grease, and various debris. The frequency of cleaning a sewer line is determined by the cleaning history needs, with the goal of preventing sewer line blockage and overflows.

Cleaning
Crews clean and maintain sewer mainlines on a daily basis. It takes approximately two years to complete an entire cycle of cleaning and maintenance of the 250 miles of lines. NSD cleans the lines in a variety of ways using the following equipment:

	Rodder The Rodder is used to remove roots, heavy grease, and other obstructions from inside the sewer lines by quickly rotating a hydraulically driven continuous steel cable rod with a cutting blade or saw attached to the leading cable.
	Hydro The Hydro cleans grit and grease accumulated from sewer mains with water pressure, scouring the inside of the pipes. The Hydro is used primarily for cleaning sewer lines that have the highest potential for blockage, mostly due to grease being discharged into the sewer lines. These areas are described as "hot spots".
	Vactor The Vactor is used for regular sewer line maintenance. It has a telescoping rotating hose reel with a nozzle at the end of the hose. With the high-pressure spray of 2000 pounds per square inch (psi), the water effectively breaks up blockages in sanitary lines and flushes out debris. The Vactor also uses a high volume vacuum to remove broken up grit and debris. The main function of this equipment is to clean the whole sewer system approximately every two years.
	TV Truck A crew is in operation nearly every day, televising NSD's sewer system with a Closed Circuit Television camera. The camera is driven down the sewer mains looking for problems in the system such as roots intruding in the line, cracks or broken lines, and off set pipes. All televising is recorded on videotape for future reference. NSD also uses a mini-cam to televise smaller diameter pipes. The mini-cam can travel through a pipe as small as 3" in diameter. These smaller pipes are usually televised whenever an emergency service call is requested due to a blockage or overflow.
	Plug-Up Truck The Plug-up Truck has equipment designed for sewer line emergencies as well as regular maintenance. One of the primary pieces of equipment on the plug-up truck is the gas-powered Eel. The eel is a hand-driven rodding machine with sections of stainless steel rods with a 4" diameter saw connected to the leader rod. A 5 horsepower motor rotates the rods, directed down a cleanout into a lateral to cut away roots, grease, and other obstructions.
	Water Truck The water truck is used to refill the reservoirs on the hydro and vactor trucks. This keeps the units in operation at the site. The water truck is also used for dust control, special projects (watering seeds and vegetation) wetting down rock and gravel to aid in compaction, street cleaning after sewer spills or overflows onto the streets.

Construction
The NSD Collection System Department does various types of construction work for the District. Crews replace or repair on an average of 70 District sewer laterals as well as install or repair 230 clean-outs a year. Crews also repair main lines and/or replace sections of mainlines, and install and raise District manholes to street grade. The District saw cuts all streets and sidewalks on all jobs, replaces all cement, and repairs all homeowner's yards to their original or better condition.

Fats, Oil & Grease (FOG)
Napa Sanitation District administers a FOG Program, which is specifically aimed towards restaurants to reduce the amount of grease entering the sewer system. This helps reduce sewer system overflows caused by pipes clogged with grease. It also helps reduce the amount of damage caused to some of our pipes after repetition cleaning. NSD requires businesses to install and maintain a grease removal device (grease trap, interceptor or vault) depending on the type of food service business (restaurants, bakeries, etc) to collect grease as part of this program. See Pollution Prevention for more information.

Emergency Service Crews
Napa Sanitation District has an emergency on-call service 24-hours a day, every day of the year with a goal to respond to all calls within 30 minutes. NSD will clear all plugged sewer laterals from the property line and all District main lines. If the problem is in the homeowner's section of the lateral, the NSD crew will inform them of the situation. It would be the homeowner's responsibility for the upper lateral and house plumbing. Obtain emergency response by calling (707) 258-6000. Click here for more contact information.

Collection System Master Plan
In 2007, Napa Sanitation District completed a Collection System Master Plan. The plan evaluates the condition and performance of the sewer pipe collection system under both current and future (year 2030) buildout conditions. The Master Plan concluded that while the collection system has adequate dry weather capacity to handle anticipated growth, it has inadequate capacity for existing wet-weather peak flows due to excessive inflow and infiltration (I/I) entering the system. I/I occurs where there are breaks in the sewer main and lateral pipes that allow rainwater or groundwater to enter the sewer pipe system.

The Master Plan concludes that the most cost-effective solution is a mixture of I/I reduction projects and capacity upgrades to handle peak flows, as opposed to wholesale capacity upgrades to the system. Based on this recommendation, the District has initiated pilot projects to determine the sources of and best approaches for reducing I/I to the collection system. For more information on the Collection System Master Plan, call the District at 258-6000.

Sanitary Sewer System Performance
NSD began reporting sanitary sewer overflows (SSOs) electronically to the California Integrated Water Quality System (CIWQS) in May, 2007. The electronic SSO data, as well as information regarding regulatory actions, is available at www.waterboards.ca.gov/waterissues/programs/ciwgs/publicreports.shtml.