MRSC Inquiries

Utilities

Contents:

Billing and Collection
Connection Charges
Deposits
Rates
Relocation
Service Extension
Sewer
Solid Waste
System Development Charges
Termination
Undergrounding
Water

Billing and Collection

Must a city provide utility service to a person who has declared bankruptcy?
A city may not refuse to provide service or discontinue service based on the filing of a bankruptcy petition. However, a city should bill for services provided to the customer after the date of the bankruptcy filing. A city can also require a security deposit equal to the charges for two months of service. After the filing of a bankruptcy petition, a city cannot take further action to collect delinquent charges that were due prior to the filing of the petition.
May a local government adopt a policy of not taking action to collect on overdue utility bills that are less than the collection costs?
Yes, a city council or board of county commissioners may adopt a policy that establishes a de minimis amount that the city or county will not seek to collect. The policy should make clear that if bills accumulate and cause the amount due to go over the minimum, then collection procedures would be followed. The amount should be set at a level that makes sense, figuring in the cost of staff time, postage, etc.
Is there a provision in state law requiring a ten-day grace period for delinquent utility bills?
There is no such provision in state law. Once a utility bill is delinquent, the city may take steps to collect the delinquent utility bill. These steps could include termination of utility service after proper notice has been given.
Is there a new law that affects the ability of a city to collect unpaid utility charges after property is sold?
New legislation that is effective January 1, 1997 creates a mechanism by which unrecorded liens, such as those for water service, are identified and satisfied at the time real property is sold. See chapter 60.80 RCW. Unless the purchaser and seller otherwise agree in writing, the seller is responsible for satisfying unrecorded utility liens at closing.
The closing agent for the sale is required to request a final billing from the utility, to which the utility must respond in a certain time period. If the utility does not respond within that time period, the unrecorded lien for charges incurred prior to the closing date is extinguished. If the utility does not receive a written request for a final billing, or if the utility complied and payment of the final billing is not provided, the utility may recover unpaid charges incurred prior to closing from the purchaser or from the seller or the person or persons who actually incurred the charges.
May a city impose a delinquency charge on an overdue utility account?
Cities have wide latitude to regulate utility service rates. (RCW 35.67.020 and 35.92.010) Cities can impose both a late penalty and interest on delinquent payments. Interest would only be allowed up to eight percent for overdue sewer bills (RCW 35.67.200). There is no particular limit placed on penalties.
When determining bill delinquency, does a city use the post office cancellation date or the date payment was actually received?
RCW 1.12.070 provides that any payment to any political subdivision, which would include cities, by means of the U.S. Mail, shall be deemed filed and received by the receiving agency as of the date shown by the Post Office cancellation mark.
Also, this statute provides that if the date provided for filing a report, claim, tax return or remittance falls upon a Saturday, Sunday, or holiday, then the filing will be considered timely if performed on the next business day.
How far back can a city go in correcting for underbilling a utility customer?
Arguably the city can go back six years based on RCW 4.16.040(2), which applies to an account receivable in the ordinary course of business. If the customer cannot pay the amount owed in a lump sum, an installment plan (with the going rate of interest charged) could be set up.
Is a utility payment or other payment due to a city timely if it is postmarked on the date it is due?
Yes. RCW 1.12.070 provides that any such payment shall be deemed "filed and received" by the city on the date shown by the "post office cancellation mark" stamped on the envelope.
May a city continue to seek collection of overdue utility bills or other overdue fees from a city resident or city business after receiving legal notice that the person or company has filed for bankruptcy?
No. After a city receives formal notice of bankruptcy filing, further collection efforts are prohibited. There are certain actions which the city can take, however, such as requiring a deposit for further utility service. If you are not familiar with the legal restrictions, discuss this issue with your city attorney.
May a city or county set reasonable limits on the acceptance of loose coins in payment of utility bills, fines, or other amounts due?
Yes, in our opinion, it may. A government agency has the right to exercise reasonable administrative discretion in determining the amounts and denominations of coinage and currency it will accept in payment of utility or other charges. Several Washington jurisdictions of which we are aware will accept no more than $2.00 in coinage in payment of personal obligations. In addition, a government may require coinage that can be rolled to be acceptable tender.
Though pennies are legal tender by federal statute, courts have repeatedly held that the statute cannot be interpreted to require acceptance of a particular denomination of coin or currency and that the absolute language of the legal-tender statutes is clearly modifiable by the necessary consideration of what is reasonable under the circumstances. See 53A AmJur2d Money, 15, citing Nemser v. New York City Transit Authority, 140 Misc 2d 369, 530 NYS2d 493. In Davis v. Davis, 254 SE2d 370 (1979), the Georgia Supreme Court upheld a contempt finding against a husband who offered to pay a lump-sum alimony award in pennies and dollar bills. See, also Chappell v. Chappell, 318 SE2d 590 (1984). There is no Washington authority on this issue.

Connection Charges

Upon initial hookup, may a city charge the same water connection fee for each dwelling unit, whether it is a house, apartment or condominium?
Yes. Although some cities have lower rates for multifamily buildings, they are not required under state law. RCW 35.92.025 merely provides that the connection charges set by the city be "equitable."

Deposits

Do cities have to pay interest on utility deposits?
No. The BARS Manual, Vol. I or II, Part III, Ch. 6, p.11, states that interest on utility deposits should be deposited in the general fund. The Auditor's Office also suggests that when a city takes a utility deposit, the receipt provided should state that the city's only obligation to the utility customer is to return the deposit. Such a statement may prevent misunderstandings and save the clerk time in the future.

Rates

May a city exclude low-income senior citizens from a proposed utility rate increase?
Yes. RCW 74.38.070 specifically allows such an exemption, or a reduction, in the utility rates for low-income seniors and certain disabled individuals.
Is there a limit on the amount of the surcharge that may be charged by a water utility to outside customers?
There is no specific limit set out in state law that authorizes a city to consider location within or outside the city in determining rates. A surcharge of 50 percent was upheld in Faxe v. Grandview, 48 Wn.2d 342 (1956). The court indicated that the surcharge must be just and reasonable but there is a presumption that the rates set by the city are just and reasonable. Many cities charge a 50 percent surcharge on nonresidents and some go considerably higher.
Utility rate discounts to low income senior citizens and low income disabled citizens.
RCW 74.38.070 provides cities, towns and counties with the authority to establish reduced utility rates for low income senior citizens or low income disabled citizens. The statute provides that "low income senior citizens" and "low income disabled citizens" shall be defined by appropriate ordinance or resolution adopted by the governing body.

Relocation

May a city, by ordinance, require a telecommunications or cable provider to bear the costs of undergrounding its existing facilities when undergrounding is for aesthetic purposes only?
No. This issue is addressed in the new right-of-way legislation adopted by the 2000 legislature. RCW 35.99.060(3) provides in part:
(3) Service providers may not seek reimbursement for their relocation expenses from the city or town requesting relocation under subsection (1) of this section except: * * * * *
(c) Where the city or town requests relocation under subsection (1) of this section solely for aesthetic purposes, unless otherwise agreed to by the parties.

Service Extension

May a city refuse a request for utility service outside its boundaries but within its UGA and where the city's water and sewer service area plan defines the city's water and sewer service area as its UGA?
Although the Growth Management Act (GMA) contemplates that a city is the appropriate provider of utility services within its Urban Growth Area (UGA), the city is not obligated by the GMA to so provide at any particular time. A city likely wants to control how and when urban growth occurs within the UGA. So, providing or not providing urban services is a basic tool of this control. There is no language in the GMA that takes this tool away from cities or that obligates cities to provide urban services to an area on demand simply because it is within the UGA.

Nevertheless, a city may be obligated to provide utility (water or sewer) service outside its boundaries but within the UGA based on rules developed by case law. The general rule is that, in the absence of a contract, express or implied, a municipality cannot be compelled to supply water outside its boundaries. Brookens v. Yakima, 15 Wn. App. 464, 466 (1976). So, if there is an express contract to provide utility service, a city is contractually obligated to provide that service. An implied contract can arise "where a municipality holds itself out as a public utility willing to supply all those who request service in a general area." Brookens, 15 Wn. App. at 466-67. A city may also have a duty to supply water or sewer service "where a city is the exclusive supplier of sewer or water service in a region extending beyond the borders of the city." Yakima County Fire Prot. Dist. No. 12 v. City of Yakima, 122 Wn.2d 371, 381-82 (1993).

But that duty, if it arises, is not absolute; a city may deny water or sewer services if it lacks the needed capacity. Yakima Fire Prot. Dist., 122 Wn.2d at 382. Also, the duty to provide the service is "subject to such reasonable conditions, if any, as the law may allow." Id. An example of such a reasonable condition, as was presented in the Yakima case, is that the property owner agree to annexation.

A case where a Washington appellate court found a duty to supply utility service within the entire UGA was in Nolte v. City of Olympia, 96 Wn. App. 944 (1999), where the city admitted that it was the sole provider of water and sewer service to the UGA.

The bottom line answer is "it depends." The fact that the city's adopted water and sewer service area plans are defined as their UGA boundaries may be a factor in favor of there being a duty to supply those services.
Is the city required to pay for the cost of extending sewer or water service within the city?
The city is not required to extend sewer or water service to all properties within the city at city expense. Most cities enter into latecomer agree-ments with the developer which include payback agreements for those who initially constructed the sewer or water service extension.

Sewer

May public restrooms be funded out of the sewer fund?
Yes. A 1997 amendment to RCW 35.67.010 specifically defines the term "system of sewage" to include "public restroom and sanitary facilities."
Is there a mechanism for a city or county to help private property owners pay for a sewer installation and then be reimbursed, with interest, over a time period?
Yes. Legislation was passed in 1998 (RCW 35.67.360) implementing the constitutional amendment approved by voters in November 1997 allowing municipal storm water and sewer utilities to make loans for storm water and sewer conservation and efficiency. Counties, cities, towns, and special districts can now use utility operating revenues to assist homeowners and businesses in acquiring and installing materials and equipment that will conserve or allow for more efficient use of municipal storm water and sewer services. The amendment to the state constitution expands the authority already available for energy (weatherization) and water conservation assistance, and establishes that these loans are not an improper loan of public credit.
Can a city initiate and finance a latecomers cost reimbursement program for sewer and water improvements similar to those for street improvements under chapter 35.72 RCW?
No, RCW 35.91.020 does not authorize cities and counties to initiate and finance a 15-year cost recovery program for water and sewer improvements without the participation of a private property owner. A city utility can, however, under RCW 35.92.025, institute a system development connection charge for financing sewer and water improvements, applicable to all property owners seeking to connect to the water or sewer system for a ten-year period, which serves a similar purpose to a city-financed latecomers reimbursement program. The programs are not the same and the specific statutory requirements of each must be followed.
RCW 35.72.050 was amended in 1997 (chapter 158, Laws of 1997) to authorize a city or county to create an assessment reimbursement area on its own initiative, without the participation of a private property owner, for financing the entire cost of street or road improvements. The city or county is the sole beneficiary of the reimbursements under this alternative cost recovery program for street improvements. RCW 35.91.020 allows cities and counties to create private developer cost reimbursement programs for construction of water and sewer facilities which are similar to the street improvement reimbursement programs authorized by RCW 35.72.010 through .040. There is no provision in chapter 35.91 RCW similar to RCW 35.72.050 which would allow cities and counties to initiate and finance sewer and water reimbursements and then become the sole beneficiary of the reimbursements.

Solid Waste

What notice must cities provide, under new legislation, before increasing solid waste collection rates?
New legislation requires cities that contract for solid waste collection service, or provide it themselves, to notify the public of proposed rate increases for that service. The notice may either be mailed to each affected ratepayer or published once a week for two consecutive weeks in a newspaper of general circulation in the collection area. The notice should be provided at least 45 days prior to the proposed effective date of the rate increase. See RCW 35.21.157.

System Development Charges

May the city impose its system development charges outside the city limits but within its urban growth area?
Yes, cities do have the authority to impose systems development charges outside their city limits. RCW 35.92.025 provides cities with the authority to impose such charges in connection with utility hook-ups. There is no limitation in this statute which would prohibit a city from imposing these charges outside the city limits. Cities have clear authority to provide utility service outside their corporate limits.
This opinion is not affected by the case of Nolte v. City of Olympia, 96 Wn. App. 944 (1999), a recent Court of Appeals decision that invalidated impact fees which were imposed by the city on property located outside the city limits. The court held that the city lacked the authority to impose impact fees outside the city limits. The decision is limited to impact fees, which are distinguishable from the systems development charges. The court in Nolte did hold that the city in this case was a public utility in the area in question and had an obligation to provide service but subject to the reasonable conditions imposed by a city that the law allows. A reasonable systems development charge is allowed by the law and so may be imposed outside the city limits even in view of the holding in the Nolte case.

Termination

May a city terminate water utility service to a customer who is delinquent in paying water bills?
There is clear authority under state law, RCW 35.21.290 - .300, for a city to terminate water utility service to a customer who is delinquent in paying his water bills.
May a city terminate water utility service in order to enforce the payment of a delinquent sewer bill?
RCW 35.67.290 provides authority for the termination of water utility service in order to enforce the payment of delinquent sewer bills if a city operates its own water system as well as sewer system.
What procedures must be followed before utility service may be terminated?
A decision of the U.S. Supreme Court in Memphis Light, Gas and Water Division v. Craft, 436 U.S. 1, 98 S.Ct. 1554 (1978), indicated that due process considerations require that certain notice procedures must be satisfied before utility service may be terminated. The notice requirements that are mandated by due process are not very burdensome. The basic procedural requirements that must be met may be summarized as follows:
- The city must give written notice to the customer prior to termination of utility service.
- All written notices advising of the termination must clearly and in layman's terms inform the customer of the available opportunities to present his objections to the bill to the municipality, and identify the telephone number, address, and department of the person who will handle the complaint. The opportunity for this informal hearing must be available in advance of the termination date.
- The municipal employee responding to the customer communication as outlined in the written notice must have the authority to review the facts and files, to correct any errors in the billings, and arrange for credit terms.
How much notification must be given before the water is shut off for nonpayment of charges?
The courts require notice and an opportunity for hearing before utilities are shut off. Although the statutes do not provide a time frame for notice, this time frame should be reasonable. Once a payment is past due, notice has been given and there has been an opportunity for a hearing, the water could be shut off without further delay.
If customer has not received notice for termination of utility service, may city terminate service?
If the city has followed the procedures required for terminating utility service, including mailing notice to the property owner and posting notice on the property, then, it is our opinion that utility service could be terminated. The city is not responsible for determining in all cases whether notice has actually been received. As long as a sufficient amount of time has elapsed between the notice and the termination, then the city has complied with the applicable rules.
Is the termination of utility service the only remedy for a delinquent utility bill?
No. The authorization to terminate utility service for failure to pay the water bill in RCW 35.21.290 - .300 is an alternative but is not the only available remedy. Other available remedies include small claims court, a collection agency, and use of superior court, if the amount involved is sufficient.
Are businesses and residences treated differently with respect to city's authority to shut off water service for nonpayment?
No. Businesses and residences are not treated differently with respect to the city's authority to shut off water service for nonpayment of charges.
Must the city notify the Health Department upon termination of water service to a customer for delinquent charges?
There is no statutory requirement that the city notify the health department when it has shut off water service to a utility customer because of delinquent utility charges. The city certainly could notify the health department, but it is not statutorily required.
May city terminate water in the winter for nonpayment of water charges?
There is no statute or principle of law that would prohibit a city from shutting off the water for nonpayment during the winter.
May the city terminate water service to a building with a fire sprinkler system?
Yes. The fact that a building is protected by a fire sprinkler system does not obligate the city to continue to provide water service if the customer does not pay the water bill. Proper notice before termination must be given.
May city terminate water service at a house where children live?
The fact that children may live in a residence which is subject to water shut-off for nonpayment of water charges has no relevance to the legal ability of the city to shut off service.
Must water service terminated for nonpayment be restored if the last four months& bills are paid?
Yes, water service must be restored. This is the intent of the provisions in RCW 35.21.290 - 35.21.300. These statutes indicate that there is a lien for delinquent water charges, although the lien may only be enforced by termination of service. These statutes indicate that this remedy is not available for charges more than four months past due. Therefore, if the last four months water bills are paid, then water service must be restored.
This does not mean that the remainder of the bill is forgiven, but it only limits the remedy that may be utilized to collect the other delinquent charges.

Must a city give notice to a tenant before shutting off utility service at the request of the landlord who has the utility account, or when the landlord fails to pay the bill?
Although there have been no reported court cases on this issue in this state, some federal courts have concluded that due process requires that notice be provided to the tenant when water service is to be terminated based on actions of the landlord. In some cases, the courts have also required that the tenant be allowed to have the utility account placed in his or her name. A few cities in this state have settled litigation on this issue by agreeing to procedures that provide both for notice and the opportunity for the tenant to initiate a utility account. This is an issue that is receiving more attention lately, and cities should be aware of the trend toward providing tenants with procedural protections.
If a city has sent out a notice regarding termination of water service due to an unpaid water bill, can the city still shut off the water if the customer offers to make a partial payment?
Water service can be shut off until the bill is paid in full. RCW 35.21.300 authorizes water service termination until "the delinquent and unpaid charges are paid." However, if more than four months of charges are delinquent, and a "partial payment" covers the unpaid charges for the last four months of water service, then service must be restored upon receipt of this payment. Note, however, that a city cannot refuse to provide water service to new tenants who are not responsible for delinquent, unpaid charges.
May a city refuse to provide water service to a new tenant because of a prior tenant's delinquent utility bill?
No. This is the specific holding in the case of O'Neal v. Seattle, 66 F.3rd 1064 (1995). Refusing to provide utility service to an innocent third party, the new tenant, because of the debt owed by the prior tenant, was held to be unconstitutional. The delinquent bill is still a debt owed the city but this particular remedy to collect is not an option.

Undergrounding

May a city or county, by ordinance, require a utility to bear the costs of undergrounding its existing facilities when undergrounding is for aesthetic purposes only?
No, not in our opinion. Although a recent federal district court summary judgement order in City of Auburn v. U.S. West Communications, No.C98-5595FDB (W.D.WA, November 15, 1999) held that utilities may be required to bear the cost of relocating (or undergrounding) their existing facilities "when required for the convenience of the public" or by reasons of "public necessity," this rule should not apply where the only reason for undergrounding is aesthetic. The required public necessity or convenience is generally found when a city or county is widening a street or changing the grade, and utility relocation or undergrounding is thus necessary. It would appear untenable that a city or county could simply require a utility to bear the cost of undergrounding existing facilities whenever the city or county deems it necessary for aesthetic reasons. That could put an intolerable financial burden on utilities. The Auburn case does not support such a position.

Water

How can a municipality benefit from water conservation?
Water conservation offers these benefits:
- Reduction in operating costs
- Reduction in electric energy consumption
- Extension of existing system without the costs of expansion
- Compensation for possible water system inadequacies
Has the state prohibited the sale of some plumbing fixtures?
Yes. RCW 19.27.170 adopted state-wide performance standards for plumbing fixtures sold, installed, or approved for installation. Effective July 1, 1993 the following standards apply:
Since the older style toilets may use from 6 to 8 gallons per flush, these new low-flow fixtures will reduce the normal domestic home water usage.
Will our water demand reduce as a result of these low-flow fixtures?
Since these fixtures will initially appear only in new or remodeled homes, there will be an extended period before their effect is noticed in most municipal water utilities. However, ultimately the domestic water usage will reduce from its present 75 to 80 gallons per day towards 45 to 50 gallons per day as a result of these new fixtures and other water conservation habits.
What other water conservation measures are being used by other municipalities?
Recognizing that an effective water conservation program must be based upon the customers understanding of the need for the program and the benefits that they will receive from such a program, some municipalities are setting examples by developing water-wise gardens in their cities and towns.
What is a water-wise garden?
Over the years, hundreds of low-water usage plants have evolved. Water-wise gardens use these low-water usage plants that tolerate drought conditions and still maintain their foliage and color. Lists of water-wise plants are available from MRSC.
May city water utilities offer water reduction devices to their customers?
RCW 35.92.017 authorizes a municipal water utility to provide water conservation literature and equipment to its customers to facilitate water conservation. Many utilities, such as Seattle, have distributed water conservation information and water conservation kits to their customers.
What is an "increasing block schedule" in a water rate?
The "inverted" or "increasing block schedule" has been adopted by some water utilities as a form of conservation pricing. Most utilities use a "declining block schedule" that was justified by the fact that the utilities experienced decreasing costs per unit of volume through economics of scale. However, as sources of supply dwindle, and costs of treatment and testing increase, many utilities are unable to safely meet their peak demand periods, due primarily to residential lawn sprinkling.
The "increasing block schedule" has a larger unit cost as the customers demand increases through the specific steps or blocks in volume.
Most water utilities have several steps in their rate structure, with a lesser unit charge as the steps of use increase. However, rather than reducing the cost per unit of water as the volume rises, they are maintaining the same unit cost or only slightly increasing the first step cost, but reducing the quantity in the first step. The unit cost in the second step is increased and the volume also reduced. A third step unit cost is also increased with a slight reduction in quantity.
By applying this "increasing rate schedule" to customers with a 3/4 inch or 1 inch meter, (usually the low-volume residential customers), while maintaining a modified "decreasing rate schedule" for all other meter sizes, the utility might effectively reduce the peak sprinkling demands without penalizing the large industrial water users.
What are the basic steps in developing a water rate schedule?
The basic steps to set a water rate are as follows:
- Estimate annual system expenses for the coming five years;
- Estimate annual water volumes to be sold for the coming five years. Allow for reduction due to water conservation measures and low-volume plumbing fixtures required as of July, 1993;
- Using the present water rate schedule, calculate estimated revenue;
- Calculate annual shortfall;
- Determine if rate reduction is to be provided to senior citizens or low income families;
- Using various rate structures, calculate annual projected revenues;
- Select the rate structure that best provides the needed income, and is fair and equitable to all customer classifications.
Can a city initiate and finance a latecomers cost reimbursement program for sewer and water improvements similar to those for street improvements under chapter 35.72 RCW?
No, RCW 35.91.020 does not authorize cities and counties to initiate and finance a 15-year cost recovery program for water and sewer improvements without the participation of a private property owner. A city utility can, however, under RCW 35.92.025, institute a system development connection charge for financing sewer and water improvements, applicable to all property owners seeking to connect to the water or sewer system for a ten-year period, which serves a similar purpose to a city-financed latecomers reimbursement program. The programs are not the same and the specific statutory requirements of each must be followed.
RCW 35.72.050 was amended in 1997 (chapter 158, Laws of 1997) to authorize a city or county to create an assessment reimbursement area on its own initiative, without the participation of a private property owner, for financing the entire cost of street or road improvements. The city or county is the sole beneficiary of the reimbursements under this alternative cost recovery program for street improvements. RCW 35.91.020 allows cities and counties to create private developer cost reimbursement programs for construction of water and sewer facilities which are similar to the street improvement reimbursement programs authorized by RCW 35.72.010 through .040. There is no provision in chapter 35.91 RCW similar to RCW 35.72.050 which would allow cities and counties to initiate and finance sewer and water reimbursements and then become the sole beneficiary of the reimbursements.
What factors can a city consider when setting water utility rates?
The primary state statute that applies to this subject is RCW 35.92.010. This statute actually gives very broad flexibility to a city in regard to setting water rates for its customers.
First of all, this statute provides broad authority to a city to construct and operate a water utility system. It also provides that the city has full power to regulate and control the use of water and the distribution and price charged for the water service. The statute does indicate that the rates charged must be uniform for the same class of customers or service.
In regard to classifying customers, the statute gives great discretion to the city council to consider any matter which presents a reasonable difference as a ground for distinction. The statute lists of number of examples such as difference in cost of service to various customers, location of the customers within and without the city, difference in cost of maintenance and repair, different character of service and a number of others which I will not list here. The statute clearly says the city may consider any or all of the factors listed in establishing classifications. Clearly a city has great latitude in establishing classifications of customers for the water utility and then establishing rates for the different classifications.
It is important to note that the statute does provide one limitation on the discretion of the city to establish rates for water use. RCW 35.92.010 specifically provides that no rate shall be charged that is less than the cost of the water and service to the class of customers served.
Your primary focus is apparently establishing rates and charges for the water utility. However, note that RCW 35.67.020 is a very similar statute which applies to a city sewer utility service. Much of the language in RCW 35.67.020 is identical or nearly identical to that in RCW 35.92.010 for water service and the city also has great flexibility is classifying customers and setting rates for the sewer utility.
What is the minimum allowable water pressure?
In the September issue of Municipal Research News, we referenced the provisions of WAC 246-290-420(4) indicating that the minimum allowable water pressure at the customer's service meter must be no less than 20 pounds per square inch (psi) under MID conditions. However, one of our readers, correctly pointed out that WAC 246-290-230, which applies to new water distribution system construction, provides in part:
This is a more restrictive requirement than WAC 246-290-420(4) which requires a minimum of 20 psi under MID conditions, excluding fire flow.
Therefore, existing water systems must provide a minimum water pressure of 20 psi at the customer's service meter, or property line under MID conditions per WAC 246-290-420(4); while all new water systems must be designed to provide a minimum water pressure of 30 psi at the service meter or property line per WAC 246-290-230.
MID refers to "maximum instantaneous demand," which means the maximum rate of water use, excluding fire flow, experienced or expected within a defined service area at any instant in time.