Chapter 3 - Current Wastewater System

Within the City and its Urban Growth Area, the Wastewater Utility is responsible for collecting wastewater from residences and businesses at the point where privately owned pipes enter the street system. Wastewater flows through City-owned and maintained sewer infrastructure to LOTT’s Budd Inlet Treatment Plant, where it is treated and either discharged to Budd Inlet, or reclaimed for beneficial uses. City operations and maintenance staff ensure the safe conveyance of the wastewater flows from the City’s extensive pipe and pumping systems to LOTT’s infrastructure.

Figure 3.1 is a conceptual diagram showing the components of the City’s sewer system.

View Figure 3.1 Components of the Collection System

Gravity sewer pipes and regional pumps (lift stations) are the conventional way to convey wastewater from homes, businesses and other buildings to central treatment facilities. Wastewater flow in sewer mains generally follows the street system downhill. If needed, it is pumped by a lift station over higher elevations in a force main and then continues flowing by gravity to one of several large LOTT transmission pipelines which convey it to the LOTT Budd Inlet Treatment Plant.

Olympia’s wastewater collection system consists of approximately 185 miles of gravity sewer mains, 33 lift stations (including three privately-owned ones that the Utility operates and maintains under contract), and 8.5 miles of sewer force mains. It also includes approximately 1860 residential and commercial STEP (septic tank effluent pumping) systems and 140+ grinder pumps, which all pump sewage from an individual home or business into the collection system. Those pipes include approximately 29 miles of STEP pressure sewers and over one mile of grinder force main. Maintenance of these systems is a key responsibility of the Wastewater Utility.

There are also about 4,145 privately-owned and managed onsite sewage systems (OSS) in Olympia and its UGA. Thurston County and the City of Olympia jointly regulate the permitting and use of these systems. Property owners are responsible for maintaining these systems. See Chapter 4 for more details about onsite systems.

The following sections describe in more detail each of the main components of the wastewater collection system:

• Gravity collection system

• Lift stations and force mains

• STEP systems

• Grinder pump systems

See Chapter 10 for an assessment of these components and an analysis of their capacity to handle current and projected wastewater flows.

3.1 Gravity Collection System

About 87% of our customers are served through a gravity sewer connection. Sewer pipes, usually buried beneath the center of streets, convey wastewater along typically straight runs of pipes between manholes. Manholes are located at junctions where the pipe changes direction and at intervals of 400 feet or less to allow access for inspection and maintenance. Cleanouts are often located at the upstream end of a pipe instead of a manhole if the sewer does not continue on.

Olympia’s collection system includes about 185 miles of gravity sewer pipes, ranging from four to 42 inches in diameter, and approximately 4,000 manholes and over 1,000 cleanouts. The LOTT system has another 16 miles of gravity sewer interceptors in Olympia’s sewer service area. Appendix M includes detailed mapping of the sewer system.

Table 3.1 summarizes the inventory of gravity collection pipes, showing diameter, length and materials. Most of the Utility’s pipes are made of either concrete or polyethylene (PVC). Since the mid-1970s PVC piping has become the industry standard for sanitary sewers. PVC pipe is durable, easy to construct, resistant to corrosion and relatively inexpensive. Recently, high density polyethylene (HDPE) pipe has been promoted as a more environmentally-friendly alternative to PVC pipe because it uses a less toxic manufacturing process than PVC. In addition, many of the older sections of the collection system contain pipes made of vitrified clay (VC), asbestos cement (AC), cast iron (CI) and ductile iron (DI). The condition of these pipes varies with age and type of materials.

 

Table 3.1

Gravity Sanitary Sewer Pipe Inventory (feet)

Pipe Diameter (inches)

Concrete

PVC

VC

AC

CI/DI

HDPE

Steel Trestle

Other or Unknown

TOTAL

4

302

30

 

482

 

 

 

 

814

6

38,086

7,335

16,870

1,000

274

 

 

267

63,832

8

248,566

386,213

48,906

8,202

6,178

3,800

 

317

702,182

10

31,357

12,739

12,331

 

701

 

215

 

57,343

12

33,634

22,065

4,319

 

 

 

 

159

60,177

14

 

 

654

1,681

36

1,111

 

 

3,482

15

21,321

16,103

9,276

109

134

 

 

 

46,943

18

19,286

11,294

2,039

 

991

 

 

 

33,610

20

 

 

606

623

 

 

 

 

1,229

21

1,606

241

 

 

 

 

 

 

1,847

22

 

 

584

 

 

 

 

 

584

24

4,637

151

465

 

123

 

 

 

5,376

30

3,384

 

 

 

 

 

 

 

3,384

36

1,726

 

 

 

 

 

 

 

1,726

42

884

 

 

 

 

 

 

 

884

unknown

290

 

 

 

 

 

 

592

882

Total lengths of each type of pipe, and their percentage of total system length

Feet

405,079

456,171

96,050

12,097

8,437

4,911

215

1,336

984,296

Miles

76.7

86.4

18.2

2.3

1.6

< 1

< 1

< 1

185

Percentage

41%

46%

10%

1%

1%

< 1%

< 1%

< 1%

100%

3.2 Lift Stations and Force Mains

Olympia’s rolling terrain requires the use of lift stations (also known as pump stations) to push wastewater over rises through force (pressurized) mains to the nearest gravity sewer that can carry flows further downstream without pumping. The City owns 30 lift stations and operates three others owned by St. Peter’s/Providence Hospital, South Puget Sound Community College and the Cooper Glen Apartments in the Overhulse Drive area adjacent to The Evergreen State College campus. Table 3.2 shows information on the City-owned lift stations and their force mains. Dedicated operations and maintenance staff oversee the operation of these critical systems.

The lift station system has about 8.5 miles of force mains, ranging from 4 to 30 inches in diameter. The Utility’s force mains are made of concrete, asbestos cement (AC), polyvinyl chloride (PVC), or high density polyethylene (HDPE) as shown in Table 3.3.

Within Olympia’s Sewer Service Area, the LOTT Alliance owns and operates another two lift stations and two miles of associated force mains.

Twenty eight of our lift stations are of a wet/dry well design with two separate below-grade chambers; the wet well holds the wastewater, and the dry well contains the pumps (usually two, which alternate pumping under normal conditions), controls and electrical equipment. In the other five stations, a pair of submersible pumps is contained within the same wet well chamber as the wastewater, and controls are in a separate panel located above grade or in a vault separate from the wet well.

The results of the assessment of physical condition and analysis of pumping capacity are presented in Chapter 10 as the basis for determining the need for lift station upgrades. Chapter 7 addresses the technical and staffing needs to support these systems.

Table 3.2

Lift Station and Force Main Inventory

 

Name

Type

Generator

Force Main Size and Material

Construct Date

Upgrade Date

1

Water St. 1

Conc. Wet & dry wells

Yes

30" RCP

1961

1977

2

Water St. 2

Conc. Wet & dry wells

Yes

18" RCP

1961

2008

3

West Bay

Conc. Wet & dry wells

Yes

12" PVC (1985, 2012)

1961

1990, 2013

4

East Bay Drive

Flygt submersible

No

4" AC

1963

2009

5

Black Lake

Fairbanks Morse canned

Yes

6" AC

1966

2013

6

Woodcrest

Quince pneumatic ejector

No

4" AC

1968

2013

7

Holiday Hills

S&L canned

Yes

6" AC

1969

2013

8

Ken Lake

Paco submersible

Yes

4" AC

1969

1990

9

Roosevelt & Yew

S&L canned

Yes

6" AC

1970

 

10

Miller & Central

S&L canned

Yes

8" AC

1970

 

11

Goldcrest

S&L canned

Yes

6" HDPE (2012)

1970

2012

12

Jasper

Paco submersible

Yes

4" AC

1972

2010

13

Old Port 1

S&L canned

No

4" AC

1971

 

14

Old Port 2

S&L canned

Yes

4" AC

1971

 

15

Rossmoor

S&L canned

Yes

6" PVC

1978

 

16

Motel 8

S&L canned

No

4" PVC

1979

 

17

East Bay Marina

S&L canned

No

4" AC

1982

 

18

Ensign Road

S&L canned

Yes

10" PVC

1989

 

19

Woodfield

S&L canned

No

4" PVC

1990

 

20

Kempton Downs

Paco canned

Yes

6" PVC (2010)

1993

2012

21

Colonial Estates

S&L canned

No

4" PVC

1994

 

22

Division & Farwell

Myers submersible

Yes

4" PVC

1995

 

23

Miller & Ann

Cornell canned

No

6" PVC

1995

 

24

Springer

Hydronix canned

No

6" PVC

1996

 

25

Cedrona

S&L canned

Yes

6" PVC

1997

 

26

Cooper Crest

S&L canned

Yes

6" PVC

2005

 

27

Mud Bay

S&L canned

Yes

8" HDPE

2008

 

28

Briggs

S&L canned

Yes

4" PVC

2008

 

29

Division & Jackson

S&L canned

No

6" PVC

1957

2009

30

Sleater Kinney

S&L canned

No

6" HDPE

2010

 

31

Yelm Hwy

S&L canned

Yes

10" HDPE

2011

 

 

Table 3.3

Sanitary Sewer Force Main Inventory (feet)

Pipe Diameter (inches)

Concrete

Asbestos Cement

PVC

High Density Polyethylene

Ductile Iron/Cast Iron

Vitreous Clay

TOTAL

4

 

4,839

9,887

 

159

 

14,885

6

 

4,828

9,704

2,359

75

510

17,476

8

 

3,476

 

855

276

 

4,607

10

 

801

699

1496

 

 

2,996

12

 

 

2,880

 

 

 

2,880

18

108

 

 

 

 

 

108

30

1,948

 

 

 

 

 

1,948

Total lengths of each pipe type and % of total force main system length

Feet

2,056

13,944

23,170

4,710

510

510

44,900

Miles

0.4

2.6

4.4

0.9

0.1

0.1

8.5

Percentage

5%

31%

52%

10%

1%

1%

100

3.3 STEP Systems

A septic tank effluent pump (STEP) system integrates the technologies of onsite sewage (septic) systems and gravity sewers. A STEP system service at a residence or business consists of a tank where solids are collected and a pump which moves the liquid waste via a low-pressure pipe into the gravity sanitary sewer system for treatment at the LOTT facility. The solids are pumped out regularly, usually at an interval of once every seven years for residential systems, and every one to four years for commercial systems.

In low-lying areas or flat terrain, STEP systems have some construction advantages over more expensive gravity sanitary sewers and lift stations. Pipes can be buried as shallow as 36 inches, and because they are pressurized and do not rely on gravity to maintain flow they can follow the terrain. Also, because only liquids are pumped, the pipe can be small diameter. As a result, installation costs are less than gravity systems that may need deep trenching.

However, maintenance costs of STEP systems are typically higher since pumps and associated equipment may break down and the tanks must be pumped periodically to remove the accumulated solids. Also, the anaerobic STEP system effluent produces hydrogen sulfide and other gases when exposed to air at locations of discharge to the gravity collection system. Hydrogen sulfide is odorous, requiring odor control techniques, and highly corrosive, damaging to unlined concrete gravity pipes and manholes.

Furthermore, under Washington State regulations, the City must own and maintain STEP systems and eventually replace them. City operations and maintenance staff are responsible for these systems. Failure of the STEP system pump or its associated pipe system can result in sewer overflows.

Figure 3.2 is a conceptual diagram of a STEP system. As with onsite sewage systems, each home, multi-unit residence, or business requires its own STEP system.

View Figure 3.2 Conceptual Diagram of a STEP System

The Utility is currently responsible for a total of 1,860 STEP systems, including 20 commercial and multifamily STEP systems, serving approximately 12 percent of residential sewer customers with 29 miles of STEP sewer mains.

New STEP systems are not permitted in Olympia’s Sewer Service Area. All of the residential developments that were "vested" to use STEP systems are either under construction or have already been constructed. The only STEP systems allowed to be constructed now are for infill lots in existing residence subdivisions served by STEP systems.

The most extensive use of STEP systems is in southeast Olympia. Other areas are located in pockets in northeast Olympia UGA along Lilly Road; northwest Olympia UGA along Overhulse Road, 11th Avenue NW and 14th Avenue NW; and along the west slopes of West Bay and Capitol Lake. See Chapter 5 for more information on the locations and density of STEP connections and mains in each basin.

3.4 Grinder Pump Systems

A grinder pump system consists of a macerating (chopping) type pump that conveys sewage from a building through a small-diameter pressurized pipe to the City’s sewer collection system. The grinder pump is typically located in a tank located on private property. It is similar to a STEP system, but without the solids settling tank (Figure 3.2).

Before 2006, there was little effort to control the use of grinder pump systems, other than a general ban on "community" grinder pump systems, where a group of residences each have a grinder pump that connected to a common pressurized sewer main in the right-of-way.

Concurrently with the 2007 Wastewater Management Plan, the Olympia Comprehensive Plan was changed to allow the use of grinder pump systems only under certain conditions. Appendix O contains a copy of both the Grinder Pump Policy and Grinder Pump Maintenance Agreement template.

Unlike STEP systems, grinder pump systems are not owned or maintained by the City. However, the Department of Ecology’s Criteria For Sewage Works Design requires utilities to develop "uniform standards for system design, installation, operation, maintenance, and emergency response measures" for grinder pump systems. It also requires utilities to "maintain a library of operation and maintenance manuals for the type(s) of systems installed within their service territory." For these reasons, and for consistency in design and reliability of service, the City only allows Environment One (E-one) grinder pumps to be used as part of a grinder pump connection to its sewer system. See Chapter 7 of the Olympia Engineering Design and Development Standards for more information on the specific pump type, required appurtenances, and design requirements.

Currently, there are approximately 140 grinder pumps in the Olympia sewer service area, all of which are owned and operated by the property owners. This accounts for less than 1% of our customers. The Utility owns just over one mile of grinder force main. See Chapter 5 for locations of current grinder pump connections in each basin.

3.5 Neighboring Jurisdictions (LOTT Clean Water Alliance Partners)

The City coordinates regional wastewater issues with the neighboring jurisdictions of Lacey, Tumwater and Thurston County through the LOTT Clean Water Alliance staff and board of elected officials (see Section 3.6). Specific development proposals located within Olympia’s UGA are coordinated by planners and engineers at the staff level. Common operational and maintenance issues are routinely handled with field staff coordination as needed.

There are a few instances of crossover between Olympia’s sewer system and the Lacey and Tumwater systems, particularly in areas where city boundaries are complex. Two examples are the region surrounding South Puget Sound Community College, where some pipes serve both Olympia and Tumwater customers but have not been identified as LOTT pipes, and the region north of North Street and East of Capitol Boulevard, where the Olympia and Tumwater border is complicated.

Coordination with neighboring jurisdictions will grow increasingly important as LOTT decentralizes wastewater treatment into satellite reclamation facilities. These facilities will require flow diversion schemes that may, for example, direct flow generated in Olympia into Lacey sewers to reach a satellite plant located in Lacey. The timing and phasing of LOTT satellite plant construction will depend upon flow availability and diversion of flow from each of the LOTT partners.

3.6 LOTT Clean Water Alliance

The LOTT Clean Water Alliance provides wastewater treatment and reclaimed water production services for the urbanized area of north Thurston County. Its four government partners (Lacey, Olympia, Tumwater and Thurston County) formed the LOTT partnership in 1975 to jointly construct and operate wastewater treatment facilities. In 2001 the partnership was reorganized as the LOTT Alliance (now LOTT Clean Water Alliance), an independent agency, with a governing board representing the four jurisdictions. A City Council member represents Olympia on the LOTT governing board. The four local Public Works Department directors serve on a technical advisory committee, known as the Technical Sub-Committee (TSC), which typically meets each month. Individual project issues are typically resolved at a staff level.

LOTT Treatment Facilities

LOTT’s overall service area is about 82 square miles, of which approximately 36 square miles are currently served by public sewers. In the long term, the entire service area is expected to be served by community sewer. LOTT’s member jurisdictions provide sewer service to a total of over 94,000 people and over 13,000 commercial and industrial customers.

LOTT’s facilities currently include the central Budd Inlet Treatment Plant, the Hawk’s Prairie satellite water reclamation facility in Lacey, major interceptor sewer lines and three regional lift stations. A second satellite facility is planned for the Chambers Prairie area of Lacey. Table 3.4 summarizes the volume of wastewater treated for the years 2006-2011.

The treatment of wastewater at LOTT has progressed from primary treatment for solids to tertiary treatment that meets and exceeds contemporary industry standards. Since 2005, a percentage of the final plant effluent has been treated to the more stringent reclaimed water standards, primarily for irrigation and industrial uses (see below and Tables 3.4 and 3.5).

About 16 miles of LOTT’s interceptor mains and three lift stations are located in Olympia. Interceptors are located under Martin Way and Capitol Way, along Indian and Percival Creeks, along Black Lake and Cooper Point Roads, and around Capitol Lake. In many cases, the City of Olympia’s neighborhood sewer systems connect directly into the LOTT interceptors. Because of these connections, potential problems or capacity-related issues affecting the LOTT system may directly impact Olympia wastewater customers.

Table 3.4

Volume of Wastewater Treated by LOTT (million gallons)*

 

2006

2007

2008

2009

2010

2011

Budd Inlet Treatment Plant

Daily Average

12.10

11.07

10.19

10.11

10.85

11.54

Minimum Monthly Average

8.40

8.67

8.31

8.53

8.33

8.97

Maximum Monthly Average

19.30

15.31

13.88

11.53

14.62

15.84

Peak Flow

38.19

48.48

26.36

48.64

33.18

33.81

Martin Way Reclaimed Water Plant

Daily Average

0.67

0.67

0.57

1.00

1.04

0.65

*    Source: LOTT 2012 State of the Utility Report.

Wastewater Resource Management Plan

LOTT’s long-range Wastewater Resource Management Plan, completed in 1998 and updated annually, sets the stage for a decentralized approach to wastewater management in the Lacey-Olympia-Tumwater urban growth areas. As population grows and demand for wastewater treatment increases, LOTT will be recycling the additional wastewater instead of discharging it into Budd Inlet after treatment. Wastewater will be treated to Class A Reclaimed Water standards and re-used for non-potable purposes and groundwater recharge. As development occurs, small units of treatment and reuse capacity will be added "just in time." During the time needed to plan, design and build new recycling facilities, additional wastewater will be handled through reserve capacity in the Budd Inlet Treatment Plant for discharge to Budd Inlet and ongoing flow reduction projects.

LOTT’s production of Class A Reclaimed Water began in 2005 with completion of the Reclaimed Water Facility at the Budd Inlet Treatment Plant. Construction of the first satellite facility, the Hawks Prairie Reclaimed Water Satellite in Lacey (also known as the Martin Way Reclaimed Water Plant), was completed in 2006. It diverts wastewater flows from Lacey that would otherwise have been conveyed to the Budd Inlet Treatment Plant. Martin Way has two million gallons per day (mgd) of treatment capacity, expandable to five mgd. Groundwater recharge basins in northeast Lacey will provide at least five mgd of recharge capacity. A second satellite facility is planned for the Chambers Prairie area of Lacey.

Table 3.5

Reclaimed Water Production Average, by LOTT (million gallons per day)*

 

2006

2007

2008

2009

2010

2011

Budd Inlet Reclaimed Water Plant

0.50

0.46

0.38

0.42

0.44

0.49

Martin Way Reclaimed Water Plant

0.46

0.60

0.54

0.94

1.05

0.65

Total

0.96

1.06

0.92

1.36

1.49

1.14

*    Source: LOTT 2012 State of the Utility Report.

Note that Table 3.4 shows total water treatment by LOTT, and Table 3.5 shows reclaimed water production. The difference between the two values for any given year suggests the volume of treated water discharged to receiving waters.

LOTT’s Wastewater Resource Management Plan is now known more familiarly as the "Highly Managed Plan" because it requires continual monitoring, planning and evaluation of future capacity needs. To identify changes or additions to planned capital projects or programs, LOTT annually analyzes flow and capacity - including treatment capacity, capacity to use or discharge treated water, and conveyance pipeline capacity.

To meet its facility plan requirements for wastewater treatment, the City of Olympia incorporates the LOTT Wastewater Resource Management Plan by reference into its Wastewater Management Plan. This was authorized April 10, 2001 by Olympia City Council adoption of Ordinance 6097, which states:

The Olympia City Council hereby approves the LOTT Wastewater Resource Management Plan’s Highly Managed Alternative, of November 1998, and directs that said Plan be incorporated into the City’s Comprehensive Plan and General Sewer Plan at the time of the next update.

LOTT’s Capital Improvement Projects

Like the City of Olympia, LOTT annually updates its Capital Improvements Plan (CIP). LOTT looks at its capital projects planning in both a near term (six-year) view, and a longer life-cycle (35-year) view. LOTT’s 2012-2018 CIP, including its proposed 2012 Capital Budget, is summarized in Table 3.6.

Table 3.6

LOTT 2013 Capital Budget and 2013-2018 CIP*

Project Categories

2013 Capital Budget

2013-2018 CIP

System Capacity

$21,098,812

$52,848,617

New Capacity

$4,538,995

$10,237,521

Asset Management

$2,969,411

$5,108,504

Support Services and Projects

$9,655,370

$40,195,090

Total

$38,262,587

$108,389,732

* Source: LOTT 2013 Capital Budget and 2013 - 2018 Capital Improvements Plan

Near-term LOTT projects with direct implications to Olympia include:

• Interceptors/Manholes Inspection and Rehabilitation (Ongoing)

• Henderson Boulevard Conveyance Pipeline (2018-2020)

• Flow Monitoring Program (Ongoing)

3.7 Pretreatment

Industrial Pretreatment

LOTT’s Industrial Pretreatment Program is designed to prevent pollutants from entering public conveyance and treatment facilities that could interfere with flow or operations, impact receiving water or biosolids quality, or threaten workers’ safety.

Through regulations appended to the LOTT Interlocal Agreement (2000), the four LOTT partner jurisdictions have adopted identical pretreatment ordinances which are enforced by the LOTT Clean Water Alliance Olympia Municipal Code Title 13 Chapter 20.

LOTT requires that discharges from permitted facilities meet industrial user permit requirements based upon federal categorical pretreatment standards and local limits. The pretreatment program includes provisions for monitoring, reporting and enforcement to ensure that potentially harmful substances are not introduced into the wastewater system. The program is updated as new users seek connections to the system, or as existing users change the pattern, quantity, quality or composition of discharge.

As of the end of 2011, there were nine Significant Industrial Users (SIUs) and 14 Minor Industrial Users permitted by LOTT in its service area. Table 3.7 summarizes those permittees that are located in the City of Olympia and discharge into the City’s sewer collection system.

LOTT’s annual Pretreatment Report has more detailed information regarding permittees as well as current and planned efforts under the Pretreatment Program.

Table 3.7

LOTT Industrial Pretreatment Permittees in Olympia

Industry

Type of Permit

Product

2011 Average Discharge (gpd)

Fish Brewing Co.

SIU

Beer

2,800

Crown Cork & Seal, Inc.

MIU

Aluminum Cans

23,0000

Georgia-Pacific Corp.

MIU

Cardboard

2,1000

J.R. Setina Manufacturing Co., Inc.

MIU

Vehicle Accessories

01

Roy’s Designs, Inc.

MIU

Metal Coatings

01

1Zero discharge facilities with the potential for hazardous or non-permitted discharges required to have an industrial user permit.

Fats, Oils and Grease

Most commercial food service establishments (FSE) produce waste products of fats, oils and grease (FOG) that if untreated at their source contribute to grease build up in the sewer collection system, leading to capacity and overflow problems, as well as treatment plant issues. City operation and maintenance staff regularly respond to conveyance problems associated with FOG. A byproduct of cooking, FOG comes from meat, fats, lard, oil, shortening, butter, margarine, food scraps, sauces, and dairy products. Grease abatement systems are required of all FSEs that produce FOG.

LOTT, in cooperation with the City of Olympia and its other partners, regularly surveys FSEs and provides technical assistance as needed to help FSEs reach compliance in addressing FOG. Enforcement of the pretreatment regulations related to FOG, codified in OMC 13.20, is the next step if an FSE does not respond to initial efforts to comply.

FSEs are not the only producers of FOG - residential wastewater can contain significant concentrations of FOG that can clog sewer service lines and gravity mains, and cause problems with the proper function of STEP tanks and grinder pump systems. Educational efforts geared toward reducing or eliminating this problem can be found at LOTT’s Water Education and Technology (WET) Science Center, on the City’s website, as well as through periodic mailings.